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Chapter 51-11R WAC

Last Update: 8/23/17

STATE BUILDING CODE ADOPTION AND AMENDMENT OF THE 2015 EDITION OF THE INTERNATIONAL ENERGY CONSERVATION CODE, RESIDENTIAL

WAC Sections

HTMLPDF51-11R-10000Chapter 1 RE—Scope and administration.
HTMLPDF51-11R-10100Section R101—Scope and general requirements.
HTMLPDF51-11R-10200Section R102—Applicability—Duties and powers of the code official.
HTMLPDF51-11R-10300Section R103—Construction documents.
HTMLPDF51-11R-10400Section R104—Inspections.
HTMLPDF51-11R-10500Section R105—Validity.
HTMLPDF51-11R-10600Section R106—Referenced standards.
HTMLPDF51-11R-10700Section R107—Fees.
HTMLPDF51-11R-10800Section R108—Stop work order.
HTMLPDF51-11R-10900Section R109—Board of appeals.
HTMLPDF51-11R-11000Section R110—Violations.
HTMLPDF51-11R-11100Section R111—Liability.
HTMLPDF51-11R-20000Chapter 2 RE—Definitions.
HTMLPDF51-11R-20100Section R201—General.
HTMLPDF51-11R-20200Section R202—General definitions.
HTMLPDF51-11R-20201Section R202.1—A.
HTMLPDF51-11R-20202Section R202.2—B.
HTMLPDF51-11R-20203Section R202.3—C.
HTMLPDF51-11R-20204Section R202.4—D.
HTMLPDF51-11R-20205Section R202.5—E.
HTMLPDF51-11R-20206Section R202.6—F.
HTMLPDF51-11R-20207Section R202.7—G.
HTMLPDF51-11R-20208Section R202.8—H.
HTMLPDF51-11R-20209Section R202.9—I.
HTMLPDF51-11R-20210Section R202.10—J.
HTMLPDF51-11R-20211Section 202.11—K.
HTMLPDF51-11R-20212Section R202.12—L.
HTMLPDF51-11R-20213Section R202.13—M.
HTMLPDF51-11R-20214Section R202.14—N.
HTMLPDF51-11R-20215Section R202.15—O.
HTMLPDF51-11R-20216Section R202.16—P.
HTMLPDF51-11R-20217Section R202.17—Q.
HTMLPDF51-11R-20218Section R202.18—R.
HTMLPDF51-11R-20219Section R202.19—S.
HTMLPDF51-11R-20220Section R202.20—T.
HTMLPDF51-11R-20221Section R202.21—U.
HTMLPDF51-11R-20222Section R202.22—V.
HTMLPDF51-11R-20223Section R202.23—W.
HTMLPDF51-11R-20224Section R202.24—XYZ.
HTMLPDF51-11R-30000Chapter 3 RE—General requirements.
HTMLPDF51-11R-30100Section R301—Climate zones.
HTMLPDF51-11R-30200Section R302—Design conditions.
HTMLPDF51-11R-30300Section R303—Materials, systems and equipment.
HTMLPDF51-11R-30310Section R303.1—Identification.
HTMLPDF51-11R-30311Table R303.1.3(1)—Default glazed fenestration U-factor.
HTMLPDF51-11R-30312Table R303.1.3(2)—Default door U-factors.
HTMLPDF51-11R-30313Table R303.1.3(3)—Default glazed fenestration SHGC and VT.
HTMLPDF51-11R-30314Table R303.1.3(4)—Default U-factors for skylights.
HTMLPDF51-11R-30315Table R303.1.3(5)—Small business compliance default table.
HTMLPDF51-11R-30320Section R303.2—Installation.
HTMLPDF51-11R-30330Section R303.3—Maintenance information.
HTMLPDF51-11R-40000Chapter 4 RE—Residential energy efficiency.
HTMLPDF51-11R-40100Section R401—General.
HTMLPDF51-11R-40200Section R402—Building thermal envelope.
HTMLPDF51-11R-40210Section R402.1—General.
HTMLPDF51-11R-40211Table R402.1.1—Insulation and fenestration requirements by component.
HTMLPDF51-11R-40213Table R402.1.3—Equivalent U-factors.
HTMLPDF51-11R-40220Section R402.2—Specific insulation requirements.
HTMLPDF51-11R-40230Section R402.3—Fenestration.
HTMLPDF51-11R-40240Section R402.4—Air leakage.
HTMLPDF51-11R-40241Table R402.4.1.1—Air barrier and insulation installation.
HTMLPDF51-11R-40250Section R402.5—Maximum fenestration U-factor and SHGC.
HTMLPDF51-11R-40300Section R403—Systems.
HTMLPDF51-11R-40310Section R403.1—Controls.
HTMLPDF51-11R-40315Section R403.2—Hot water boiler.
HTMLPDF51-11R-40320Section R403.3—Ducts.
HTMLPDF51-11R-40330Section R403.4—Mechanical system piping insulation.
HTMLPDF51-11R-40340Section R403.5—Service hot water systems.
HTMLPDF51-11R-40350Section R403.6—Mechanical ventilation.
HTMLPDF51-11R-40351Table R403.6.1—Mechanical ventilation system fan efficacy.
HTMLPDF51-11R-40360Section R403.7—Equipment sizing.
HTMLPDF51-11R-40370Section R403.8—Systems serving multiple dwelling units.
HTMLPDF51-11R-40380Section R403.9—Snow melt system controls.
HTMLPDF51-11R-40390Section R403.10—Pool and spa energy consumption.
HTMLPDF51-11R-40391Section R403.10—Other pools and spas.
HTMLPDF51-11R-40400Section R404—Electrical power and lighting systems.
HTMLPDF51-11R-40410Section R404.1—Lighting equipment.
HTMLPDF51-11R-40500Section R405—Simulated performance alternative (Performance).
HTMLPDF51-11R-40510Section R405.1—Scope.
HTMLPDF51-11R-40520Section R405.2—Mandatory requirements.
HTMLPDF51-11R-40530Section R405.3—Performance-based compliance.
HTMLPDF51-11R-40540Section R405.4—Documentation.
HTMLPDF51-11R-40550Section R405.5—Calculation procedure.
HTMLPDF51-11R-40551Table R405.5.2(1)—Specifications for the standard reference and proposed designs.
HTMLPDF51-11R-40552Table R405.5.2(2)—Default distribution system efficiencies for proposed designs.
HTMLPDF51-11R-40560Section R405.6—Calculation software tools.
HTMLPDF51-11R-40600Section R406—Additional energy efficiency requirements.
HTMLPDF51-11R-40610Section R406.1—Scope.
HTMLPDF51-11R-40620Section R406.2—Additional energy efficiency requirements.
HTMLPDF51-11R-40621Table R406.2—Energy credits.
HTMLPDF51-11R-50000Chapter 5—Existing buildings.
HTMLPDF51-11R-50100Section R501—General.
HTMLPDF51-11R-50200Section R502—Additions.
HTMLPDF51-11R-50300Section R503—Alterations.
HTMLPDF51-11R-50400Section R504—Repairs.
HTMLPDF51-11R-50500Section R505—Change of occupancy or use.
HTMLPDF51-11R-51000Chapter 6—Referenced standards.
HTMLPDF51-11R-60000Appendix C—Exterior design conditions.
HTMLPDF51-11R-60100Table C-1—Outdoor design temperatures for Washington.


PDF51-11R-10000

Chapter 1 [RE]—Scope and administration.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-10000, filed 2/1/13, effective 7/1/13.]
Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency.



PDF51-11R-10100

Section R101Scope and general requirements.

R101.1 Title. This code shall be known as the Washington State Energy Code, and shall be cited as such. It is referred to herein as "this code."
R101.2 Scope. This code applies to residential buildings and the buildings sites and associated systems and equipment. This code shall be the maximum and minimum energy code for residential construction in each town, city and county. Residential sleeping units, Group I-1, Condition 2 assisted living facilities licensed by Washington state under chapter 388-78A WAC and Group I-1, Condition 2 residential treatment facilities licensed by Washington state under chapter 246-337 WAC shall utilize the commercial building sections of the energy code regardless of the number of stories of height above grade plane.
R101.3 Intent. This code shall regulate the design and construction of buildings for the effective use and conservation of energy over the useful life of each building. This code is intended to provide flexibility to permit the use of innovative approaches and techniques to achieve this objective. This code is not intended to abridge safety, health or environmental requirements contained in other applicable codes or ordinances.
R101.4 Applicability. Where, in any specific case, different sections of this code specify different materials, methods of construction or other requirements, the most restrictive shall govern. Where there is a conflict between a general requirement and a specific requirement, the specific requirement shall govern.
R101.4.1 Mixed occupancy. Where a building includes both residential and commercial occupancies, each occupancy shall be separately considered and meet the applicable provisions of the WSEC - Commercial and Residential Provisions.
R101.5 Compliance.Residential buildings shall meet the provisions of WSEC - Residential Provisions. Commercial buildings shall meet the provisions of WSEC - Commercial Provisions.
R101.5.1 Compliance materials. The code official shall be permitted to approve specific computer software, worksheets, compliance manuals and other similar materials that meet the intent of this code.
[Statutory Authority: RCW 19.27A.025, 19.27A.045, and chapters 19.27, 19.27A, and 34.05 RCW. WSR 17-17-160, § 51-11R-10100, filed 8/23/17, effective 10/1/17. Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-10100, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-10100, filed 2/1/13, effective 7/1/13.]



PDF51-11R-10200

Section R102ApplicabilityDuties and powers of the code official.

R102.1Alternate materials, design and methods of construction and equipment. The provisions of this code are not intended to prevent the installation of any material or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. The code official shall be permitted to approve an alternative material, design or method of construction where the code official finds that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method or work offered is, for the purpose intended, at least the equivalent of that prescribed in this code.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-10200, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-10200, filed 2/1/13, effective 7/1/13.]



PDF51-11R-10300

Section R103Construction documents.

R103.1 General. Construction documents, technical report, and other supporting data shall be submitted in one or more sets with each application for a permit. The construction documents and technical reports shall be prepared by a registered design professional where required by the statutes of the jurisdiction in which the project is to be constructed. Where special conditions exist, the code official is authorized to require necessary construction documents to be prepared by a registered design professional.
EXCEPTION:
The code official is authorized to waive the requirements for construction documents or other supporting data if the code official determines they are not necessary to confirm compliance with this code.
R103.2 Information on construction documents. Construction documents shall be drawn to scale upon suitable material. Electronic media documents are permitted to be submitted when approved by the code official. Construction documents shall be of sufficient clarity to indicate the location, nature and extent of the work proposed, and show in sufficient detail pertinent data and features of the building, systems and equipment as herein governed. Details shall include, but are not limited to, the following as applicable:
1. Insulation materials and their R-values
2. Fenestration U-factors and SHGCs
3. Area-weighted U-factor and SHGC calculations
4. Mechanical system design criteria
5. Mechanical and service water heating system and equipment types, sizes and efficiencies
6. Equipment and systems controls
7. Duct sealing, duct and pipe insulation and location
8. Air sealing details.
R103.2.1 Building thermal envelope depiction. The building's thermal envelope shall be represented on the construction documents.
R103.3 Examination of documents. The code official shall examine or cause to be examined the accompanying construction documents and shall ascertain whether the construction indicated and described is in accordance with the requirements of this code and other pertinent laws or ordinances. The code official is authorized to utilize a registered design professional or other approved entity not affiliated with the building design or construction in conducting the review of the plans and specifications for compliance with the code.
R103.3.1 Approval of construction documents. When the code official issues a permit where construction documents are required, the construction documents shall be endorsed in writing and stamped "Reviewed for Code Compliance." Such approved construction documents shall not be changed, modified or altered without authorization from the code official. Work shall be done in accordance with the approved construction documents.
One set of construction documents so reviewed shall be retained by the code official. The other set shall be returned to the applicant, kept at the site of work and shall be open to inspection by the code official or a duly authorized representative.
R103.3.2 Previous approvals. This code shall not require changes in the construction documents, construction or designated occupancy of a structure for which a lawful permit has been heretofore issued or otherwise lawfully authorized, and the construction of which has been pursued in good faith within 180 days after the effective date of this code and has not been abandoned.
R103.3.3 Phased approval. The code official shall have the authority to issue a permit for the construction of part of an energy conservation system before the construction documents for the entire system have been submitted or approved, provided adequate information and detailed statements have been filed complying with all pertinent requirements of this code. The holders of such permit shall proceed at their own risk without assurance that the permit for the entire energy conservation system will be granted.
R103.4 Amended construction documents. Work shall be installed in accordance with the approved construction documents, and any changes made during construction that are not in compliance with the approved construction documents shall be resubmitted for approval as an amended set of construction documents.
R103.5 Retention of construction documents. One set of approved construction documents shall be retained by the code official for a period of not less than 180 days from date of completion of the permitted work, or as required by state or local laws.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-10300, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-10300, filed 2/1/13, effective 7/1/13.]



PDF51-11R-10400

Section R104Inspections.

R104.1 General. Construction or work for which a permit is required shall be subject to inspection by the code official or his or her designated agent, and such construction or work shall remain accessible and exposed for inspection purposes until approved. It shall be the duty of the permit applicant to cause the work to remain accessible and exposed for inspection purposes. Neither the code official nor the jurisdiction shall be liable for expense entailed in the removal or replacement of any material, product, system or building component required to allow inspection to validate compliance with this code.
R104.2 Required inspections. The code official or his or her designated agent, upon notification, shall make the inspections set forth in Sections R104.2.1 through R104.2.5.
R104.2.1 Footing and foundation inspection. Inspections associated with footings and foundations shall verify compliance with the code as to R-value, location, thickness, depth of burial and protection of insulation as required by the code and approved plans and specifications.
R104.2.2 Framing and rough-in inspection. Inspections at framing and rough-in shall be made before application of interior finish and shall verify compliance with the code as to types of insulation and corresponding R-values and their correct location and proper installation; fenestration properties (U-factor and SHGC) and proper installation; and air leakage controls as required by the code and approved plans and specifications.
R104.2.2.1 Wall insulation inspection. The building official, upon notification, shall make a wall insulation inspection in addition to those inspections required in Section R109 of the International Residential Code. This inspection shall be made after all wall and cavity insulation is in place and prior to cover.
R104.2.3 Plumbing rough-in inspection. Inspections at plumbing rough-in shall verify compliance as required by the code and approved plans and specifications as to types of insulation and corresponding R-values and protection, and required controls.
R104.2.4 Mechanical rough-in inspection. Inspections at mechanical rough-in shall verify compliance as required by the code and approved plans and specifications as to installed HVAC equipment type and size, required controls, system insulation and corresponding R-value, system air leakage control, programmable thermostats, dampers, whole-house ventilation and minimum fan efficiency.
EXCEPTION:
Systems serving multiple dwelling units shall be inspected in accordance with Section C104.2.4.
R104.2.5 Final inspection. The building shall have a final inspection and not be occupied until approved.
R104.3 Reinspection. A building shall be reinspected when determined necessary by the code official.
R104.4 Approved inspection agencies. The code official is authorized to accept reports of third-party inspection agencies not affiliated with the building design or construction, provided such agencies are approved as to qualifications and reliability relevant to the building components and systems they are inspecting.
R104.5 Inspection requests. It shall be the duty of the holder of the permit or their duly authorized agent to notify the code official when work is ready for inspection. It shall be the duty of the permit holder to provide access to and means for inspections of such work that are required by this code.
R104.6 Reinspection and testing. Where any work or installation does not pass an initial test or inspection, the necessary corrections shall be made so as to achieve compliance with this code. The work or installation shall then be resubmitted to the code official for inspection and testing.
R104.7 Approval. After the prescribed tests and inspections indicate that the work complies in all respects with this code, a notice of approval shall be issued by the code official.
R104.7.1 Revocation. The code official is authorized to, in writing, suspend or revoke a notice of approval issued under the provisions of this code wherever the certificate is issued in error, or on the basis of incorrect information supplied, or where it is determined that the building or structure, premise, or portion thereof is in violation of any ordinance or regulation or any of the provisions of this code.
[Statutory Authority: RCW 19.27A.025, 19.27A.045, 19.27A.160, and 19.27.074. WSR 17-10-063, § 51-11R-10400, filed 5/2/17, effective 6/2/17; WSR 16-02-127, § 51-11R-10400, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-10400, filed 2/1/13, effective 7/1/13.]



PDF51-11R-10500

Section R105—Validity.

R105.1 General. If a portion of this code is held to be illegal or void, such a decision shall not affect the validity of the remainder of this code.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-10500, filed 2/1/13, effective 7/1/13.]



PDF51-11R-10600

Section R106Referenced standards.

R106.1 Referenced codes and standards. The codes and standards referenced in this code shall be those listed in Chapter 5, and such codes and standards shall be considered as part of the requirements of this code to the prescribed extent of each such reference and as further regulated in Sections R106.1.1 and R106.1.2.
R106.1.1 Conflicts. Where differences occur between provisions of this code and referenced codes and standards, the provisions of this code shall apply.
R106.1.2 Provisions in referenced codes and standards. Where the extent of the reference to a referenced code or standard includes subject matter that is within the scope of this code, the provisions of this code, as applicable, shall take precedence over the provisions in the referenced code or standard.
R106.2
Application of references. References to chapter or section numbers, or to provisions not specifically identified by number, shall be construed to refer to such chapter, section or provision of this code.
R106.3 Other laws. The provisions of this code shall not be deemed to nullify any provisions of local, state or federal law. In addition to the requirements of this code, all occupancies shall conform to the provisions included in the state building code (chapter 19.27 RCW). In case of conflicts among codes enumerated in RCW 19.27.031 (1) through (4) and this code, an earlier named code shall govern over those following. In the case of conflict between the duct sealing and insulation requirements of this code and the duct insulation requirements of Sections 603 and 604 of the International Mechanical Code, the duct insulation requirements of this code shall govern.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-10600, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-10600, filed 2/1/13, effective 7/1/13.]



PDF51-11R-10700

Section R107—Fees.

R107.1 Fees. A permit shall not be issued until the fees prescribed in Section R107.2 have been paid, nor shall an amendment to a permit be released until the additional fee, if any, has been paid.
R107.2 Schedule of permit fees. A fee for each permit shall be paid as required, in accordance with the schedule as established by the applicable governing authority.
R107.3 Work commencing before permit issuance. Any person who commences any work before obtaining the necessary permits shall be subject to an additional fee established by the code official, which shall be in addition to the required permit fees.
R107.4 Related fees. The payment of the fee for the construction, alteration, removal or demolition of work done in connection to or concurrently with the work or activity authorized by a permit shall not relieve the applicant or holder of the permit from the payment of other fees that are prescribed by law.
R107.5 Refunds. The code official is authorized to establish a refund policy.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-10700, filed 2/1/13, effective 7/1/13.]



PDF51-11R-10800

Section R108Stop work order.

R108.1 Authority. Whenever the code official finds any work regulated by this code being performed in a manner either contrary to the provisions of this code or dangerous or unsafe, the code official is authorized to issue a stop work order.
R108.2 Issuance. The stop work order shall be in writing and shall be given to the owner of the property involved, or to the owner's authorized agent, or to the person doing the work. Upon issuance of a stop work order, the cited work shall immediately cease. The stop work order shall state the reason for the order, and the conditions under which the cited work will be permitted to resume.
R108.3 Emergencies. Where an emergency exists, the code official shall not be required to give a written notice prior to stopping the work.
R108.4 Failure to comply. Any person who shall continue any work after having been served with a stop work order, except such work as that person is directed to perform to remove a violation or unsafe condition, shall be subject to a fine as set by the applicable governing authority.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-10800, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-10800, filed 2/1/13, effective 7/1/13.]



PDF51-11R-10900

Section R109—Board of appeals.

R109.1 General. In order to hear and decide appeals of orders, decisions or determinations made by the code official relative to the application and interpretation of this code, there shall be and is hereby created a board of appeals. The code official shall be an ex officio member of said board but shall have no vote on any matter before the board. The board of appeals shall be appointed by the governing body and shall hold office at its pleasure. The board shall adopt rules of procedure for conducting its business, and shall render all decisions and findings in writing to the appellant with a duplicate copy to the code official.
R109.2 Limitations on authority. An application for appeal shall be based on a claim that the true intent of this code or the rules legally adopted thereunder have been incorrectly interpreted, the provisions of this code do not fully apply or an equally good or better form of construction is proposed. The board shall have no authority to waive requirements of this code.
R109.3 Qualifications. The board of appeals shall consist of members who are qualified by experience and training and are not employees of the jurisdiction.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-10900, filed 2/1/13, effective 7/1/13.]



PDF51-11R-11000

Section R110—Violations.

It shall be unlawful for any person, firm, or corporation to erect or construct any building, or remodel or rehabilitate any existing building or structure in the state, or allow the same to be done, contrary to or in violation of any of the provisions of this code.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-11000, filed 2/1/13, effective 7/1/13.]



PDF51-11R-11100

Section R111—Liability.

Nothing contained in this code is intended to be nor shall be construed to create or form the basis for any liability on the part of any city or county or its officers, employees or agents for any injury or damage resulting from the failure of a building to conform to the provisions of this code.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-11100, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20000

Chapter 2 [RE]—Definitions.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20000, filed 2/1/13, effective 7/1/13.]
Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency.



PDF51-11R-20100

Section R201—General.

R201.1 Scope. Unless stated otherwise, the following words and terms in this code shall have the meanings indicated in this chapter.
R201.2 Interchangeability. Words used in the present tense include the future; words in the masculine gender include the feminine and neuter; the singular number includes the plural and the plural includes the singular.
R201.3 Terms defined in other codes. Terms that are not defined in this code but are defined in the International Building Code, International Fire Code, International Fuel Gas Code, International Mechanical Code, Uniform Plumbing Code or the International Residential Code shall have the meanings ascribed to them in those codes.
R201.4 Terms not defined. Terms not defined by this chapter shall have ordinarily accepted meanings such as the context implies.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20100, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20200

Section R202—General definitions.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20200, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20201

Section R202.1A.

ABOVE-GRADE WALL. A wall enclosing conditioned space that is not a below-grade wall. This includes between-floor spandrels, peripheral edges of floors, roof and basement knee walls, dormer walls, gable end walls, walls enclosing a mansard roof and skylight shafts.
ACCESSIBLE. Admitting close approach as a result of not being guarded by locked doors, elevation or other effective means (see "Readily accessible").
ADDITION. An extension or increase in the conditioned space floor area or height of a building or structure.
ADVANCED FRAMED WALLS. Studs framed on 24-inch centers with double top plate and single bottom plate. Corners use two studs or other means of fully insulating corners, and one stud is used to support each header. Headers consist of double 2x material with R-10 insulation between the header and exterior sheathing. Interior partition wall/exterior wall intersections are fully insulated in the exterior wall. (See Standard Framing and Appendix A, of this code.)
AIR BARRIER. Material(s) assembled and joined together to provide a barrier to air leakage through the building envelope. An air barrier may be a single material or a combination of materials.
ALTERATION. Any construction, retrofit or renovation to an existing structure other than repair or addition that requires a permit. Also, a change in a building, electrical, gas, mechanical or plumbing system that involves an extension, addition or change to the arrangement, type or purpose of the original installation that requires a permit.
APPROVED. Approval by the code official as a result of investigation and tests conducted by him or her, or by reason of accepted principles or tests by nationally recognized organizations.
APPROVED AGENCY. An established and recognized agency regularly engaged in conducting tests or furnishing inspection services, when such agency has been approved by the code official.
AUTOMATIC. Self-acting, operating by its own mechanism when actuated by some impersonal influence, as, for example, a change in current strength, pressure, temperature or mechanical configuration (see "Manual").
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-20201, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20201, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20202

Section R202.2—B.

BASEMENT WALL. See above-grade wall and below-grade wall.
BELOW-GRADE WALL. That portion of a wall in the building envelope that is entirely below the finish grade and in contact with the ground.
BUILDING. Any structure used or intended for supporting or sheltering any use or occupancy, including any mechanical systems, service water heating systems and electric power and lighting systems located on the building site and supporting the building.
BUILDING SITE. A contiguous area of land that is under the ownership or control of one entity.
BUILDING THERMAL ENVELOPE. The below-grade walls, above-grade walls, floor, roof, and any other building elements that enclose conditioned space or provides a boundary between conditioned space and exempt or unconditioned space.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20202, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20203

Section R202.3C.

C-FACTOR (THERMAL CONDUCTANCE). The coefficient of heat transmission (surface to surface) through a building component or assembly, equal to the time rate of heat flow per unit area and the unit temperature difference between the warm side and cold side surfaces (Btu/h ft2 × °F) [W/(m2 × K)].
CIRCULATING HOT WATER SYSTEM. A specifically designed water distribution system where one or more pumps are operated in the service hot water piping to circulate heated water from the water-heating equipment to the fixture supply and back to the water-heating equipment.
CLIMATE ZONE. A geographical region based on climatic criteria as specified in this code.
CODE OFFICIAL. The officer or other designated authority charged with the administration and enforcement of this code, or a duly authorized representative.
COMMERCIAL BUILDING. For this code, all buildings that are not included in the definition of "Residential buildings."
CONDITIONED FLOOR AREA. The horizontal projection of the floors associated with the conditioned space.
CONDITIONED SPACE. An area, room or space that is enclosed within the building thermal envelope and that is directly or indirectly heated or cooled. Spaces are indirectly heated or cooled where they communicate through openings with conditioned spaces, where they are separated from conditioned spaces by uninsulated walls, floors or ceilings, or where they contain uninsulated ducts, piping or other sources of heating or cooling.
CONTINUOUS AIR BARRIER. A combination of materials and assemblies that restrict or prevent the passage of air through the building thermal envelope.
CONTINUOUS INSULATION (c.i.). Insulating material that is continuous across all structural members without thermal bridges other than fasteners and service openings. It is installed on the interior or exterior or is integral to any opaque surface of the building envelope.
CURTAIN WALL. Fenestration products used to create an external nonload-bearing wall that is designed to separate the exterior and interior environments.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-20203, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20203, filed 2/1/13, effective 7/1/13.]
Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency.



PDF51-11R-20204

Section R202.4—D.

DEMAND RECIRCULATION WATER SYSTEM. A water distribution system where pump(s) prime the service hot water piping with heated water upon demand for hot water.
DUCT. A tube or conduit utilized for conveying air. The air passages of self-contained systems are not to be construed as air ducts.
DUCT SYSTEM. A continuous passageway for the transmission of air that, in addition to ducts, includes duct fittings, dampers, plenums, fans and accessory air-handling equipment and appliances.
DWELLING UNIT. A single unit providing complete independent living facilities for one or more persons, including permanent provisions for living, sleeping, eating, cooking and sanitation.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20204, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20205

Section R202.5E.

ENERGY ANALYSIS. A method for estimating the annual energy use of the proposed design and standard reference design based on estimates of energy use.
ENERGY COST. The total estimated annual cost for purchased energy for the building functions regulated by this code, including applicable demand charges.
ENERGY SIMULATION TOOL. An approved software program or calculation-based methodology that projects the annual energy use of a building.
EXTERIOR WALL. Walls including both above-grade walls and below-grade walls.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-20205, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20205, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20206

Section R202.6F.

FENESTRATION. Products classified as either vertical fenestration or skylights.
VERTICAL FENESTRATION. Windows (fixed or moveable), glazed doors, glazed block and combination opaque/glazed doors composed of glass or other transparent or translucent glazing materials and installed at a slope of at least 60 degrees from horizontal. Opaque areas such as spandrel panels are not considered vertical fenestration.
SKYLIGHT. Glass or other transparent or translucent glazing material installed with a slope of less than 60 degrees from horizontal.
FENESTRATION AREA. Total area of the fenestration measured using the rough opening, and including the glazing, sash and frame.
FENESTRATION PRODUCT, FIELD-FABRICATED. A fenestration product whose frame is made at the construction site of standard dimensional lumber or other materials that were not previously cut, or otherwise formed with the specific intention of being used to fabricate a fenestration product or exterior door. Field fabricated does not include site-built fenestration.
FENESTRATION PRODUCT, SITE-BUILT. A fenestration designed to be made up of field-glazed or field-assembled units using specific factory cut or otherwise factory-formed framing and glazing units. Examples of site-built fenestration include storefront systems, curtain walls, and atrium roof systems.
F-FACTOR. The perimeter heat loss factor for slab-on-grade floors (Btu/h × ft × °F) [W/(m × K)].
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-20206, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20206, filed 2/1/13, effective 7/1/13.]
Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency.



PDF51-11R-20207

Section R202.7—G.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20207, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20208

Section R202.8H.

HEATED SLAB-ON-GRADE FLOOR. Slab-on-grade floor construction in which the heating elements, hydronic tubing, or hot air distribution system is in contact with, or placed within or under, the slab.
HIGH-EFFICACY LAMPS. Compact fluorescent lamps, T-8 or smaller diameter linear fluorescent lamps, or lamps with a minimum efficacy of:
1. 60 lumens per watt for lamps over 40 watts;
2. 50 lumens per watt for lamps over 15 watts to 40 watts; and
3. 40 lumens per watt for lamps 15 watts or less.
HISTORIC BUILDINGS. Buildings that are listed in or eligible for listing in the National Register of Historic Places, or designated as historic under an appropriate state or local law.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-20208, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20208, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20209

Section R202.9I.

INFILTRATION. The uncontrolled inward air leakage into a building caused by the pressure effects of wind or the effect of differences in the indoor and outdoor air density or both.
INSULATED SIDING. A type of continuous insulation with manufacturer-installed insulating material as an integral part of the cladding product having a minimum R-value of R-2.
INSULATING SHEATHING. An insulating board with a core material having a minimum R-value of R-2.
INTEGRATED ENERGY EFFICIENCY RATIO (IEER). A single-number figure of merit expressing cooling part-load EER efficiency for unitary air-conditioning and heat pump equipment on the basis of weighted operation at various load capacities for the equipment.
INTERMEDIATE FRAMED WALLS. Studs framed on 16-inch centers with double top plate and single bottom plate. Corners use two studs or other means of fully insulating corners, and each opening is framed by two studs. Headers shall be insulated to R-10.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-20209, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20209, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20210

Section R202.10—J.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20210, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20211

Section 202.11—K.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20211, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20212

Section R202.12—L.

labeled. Equipment, materials or products to which have been affixed a label, seal, symbol or other identifying mark of a nationally recognized testing laboratory, inspection agency or other organization concerned with product evaluation that maintains periodic inspection of the production of the above-labeled items and whose labeling indicates either that the equipment, material or product meets identified standards or has been tested and found suitable for a specified purpose.
listed. Equipment, materials, products or services included in a list published by an organization acceptable to the code official and concerned with evaluation of products or services that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services and whose listing states either that the equipment, material, product or service meets identified standards or has been tested and found suitable for a specified purpose.
low-voltage lighting. A lighting system consisting of an isolating power supply, the low voltage luminaires, and associated equipment that are all identified for the use. The output circuits of the power supply operate at 30 volts (42.4 volts peak) or less under all load conditions.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20212, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20213

Section R202.13—M.

manual. Capable of being operated by personal intervention (see "Automatic").
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20213, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20214

Section R202.14—N.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20214, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20215

Section R202.15—O.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20215, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20216

Section R202.16—P.

proposed design. A description of the proposed building used to estimate annual energy use for determining compliance based on total building performance.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20216, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20217

Section R202.17—Q.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20217, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20218

Section R202.18R.

READILY ACCESSIBLE. Capable of being reached quickly for operation, renewal or inspection without requiring those to whom ready access is requisite to climb over or remove obstacles or to resort to portable ladders or access equipment (see "Accessible").
REPAIR. The reconstruction or renewal of any part of an existing building for the purpose of its maintenance or to correct damage.
REROOFING. The process of recovering or replacing an existing roof covering. See "Roof recover" and "Roof replacement."
RESIDENTIAL BUILDING. For this code, includes detached one- and two-family dwellings and multiple single-family dwellings (townhouses) as well as Group R-2, R-3 and R-4 buildings three stories or less in height above grade plane.
ROOF ASSEMBLY. A system designed to provide weather protection and resistance to design loads. The system consists of a roof covering and roof deck or a single component serving as both the roof covering and the roof deck. A roof assembly includes the roof covering, underlayment, roof deck, insulation, vapor retarder and interior finish.
ROOF RECOVER. The process of installing an additional roof covering over a prepared existing roof covering without removing the existing roof covering.
ROOF REPAIR. Reconstruction or renewal of any part of an existing roof for the purposes of its maintenance.
ROOF REPLACEMENT. The process of removing the existing roof covering, repairing any damaged substrate and installing a new roof covering.
R-VALUE (THERMAL RESISTANCE). The inverse of the time rate of heat flow through a body from one of its bounding surfaces to the other surface for a unit temperature difference between the two surfaces, under steady state conditions, per unit area (h • ft2 • °F/Btu) [(m2 • K)/W].
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-20218, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20218, filed 2/1/13, effective 7/1/13.]
Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency.



PDF51-11R-20219

Section R202.19S.

SERVICE WATER HEATING. Supply of hot water for purposes other than comfort heating.
SLAB-ON-GRADE FLOOR. That portion of a slab floor of the building envelope that is in contact with the ground and that is either above grade or is less than or equal to 24 inches below the final elevation of the nearest exterior grade.
SMALL BUSINESS. Any business entity (including a sole proprietorship, corporation, partnership or other legal entity) which is owned and operated independently from all other businesses, which has the purpose of making a profit, and which has fifty or fewer employees.
SOLAR HEAT GAIN COEFFICIENT (SHGC). The ratio of the solar heat gain entering the space through the fenestration assembly to the incident solar radiation. Solar heat gain includes directly transmitted solar heat and absorbed solar radiation which is then reradiated, conducted or convected into the space.
STANDARD FRAMING. All framing practices not defined as "intermediate" or "advanced" shall be considered standard. (See Advanced Framed Wall, Intermediate Framed Wall).
STANDARD REFERENCE DESIGN. A version of the proposed design that meets the minimum requirements of this code and is used to determine the maximum annual energy use requirement for compliance based on total building performance.
[Statutory Authority: RCW 19.27A.025, 19.27A.045, 19.27A.160, and 19.27.074. WSR 17-10-063, § 51-11R-20219, filed 5/2/17, effective 6/2/17. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20219, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20220

Section R202.20—T.

thermal isolation. Physical and space conditioning separation from conditioned space(s). The conditioned space(s) shall be controlled as separate zones for heating and cooling or conditioned by separate equipment.
thermostat. An automatic control device used to maintain temperature at a fixed or adjustable set point.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20220, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20221

Section R202.21—U.

u-factor (thermal transmittance). The coefficient of heat transmission (air to air) through a building component or assembly, equal to the time rate of heat flow per unit area and unit temperature difference between the warm side and cold side air films (Btu/h • ft2 • °F) [W/(m2 • K)].
unheated slab-on-grade floor. A slab-on-grade floor that is not a heated slab-on-grade floor.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20221, filed 2/1/13, effective 7/1/13.]
Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency.



PDF51-11R-20222

Section R202.22—V.

ventilation. The natural or mechanical process of supplying conditioned or unconditioned air to, or removing such air from, any space.
ventilation air. That portion of supply air that comes from outside (outdoors) plus any recirculated air that has been treated to maintain the desired quality of air within a designated space.
vertical fenestration. All fenestration other than skylights.
visible transmittance [vt]. The ratio of visible light entering the space through the fenestration product assembly to the incident visible light, visible transmittance, includes the effects of glazing material and frame and is expressed as a number between 0 and 1.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20222, filed 2/1/13, effective 7/1/13.]
Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency.



PDF51-11R-20223

Section R202.23—W.

whole house mechanical ventilation system. An exhaust system, supply system, or combination thereof that is designed to mechanically exchange indoor air with outdoor air when operating continuously or through a programmed intermittent schedule to satisfy the whole house ventilation rates.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20223, filed 2/1/13, effective 7/1/13.]



PDF51-11R-20224

Section R202.24—XYZ.

zone. A space or group of spaces within a building with heating or cooling requirements that are sufficiently similar so that desired conditions can be maintained throughout using a single controlling device.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-20224, filed 2/1/13, effective 7/1/13.]



PDF51-11R-30000

Chapter 3 [RE]—General requirements.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30000, filed 2/1/13, effective 7/1/13.]
Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency.



PDF51-11R-30100

Section R301—Climate zones.

R301.1 General. Climate zones from Table R301.1 shall be used in determining the applicable requirements from Chapter 4. Locations not in Table R301.1 (outside the United States) shall be assigned a climate zone based on Section R301.3.
R301.2 Warm humid counties. Warm humid counties are identified in Table R301.1 by an asterisk.
R301.3 International climate zones. The climate zone for any location outside the United States shall be determined by applying Table R301.3(1) and then Table R301.3(2).
TABLE R301.1
CLIMATE ZONES, MOISTURE REGIMES, AND WARM-HUMID
DESIGNATIONS BY STATE AND COUNTY
Key: A - Moist, B - Dry, C - Marine. Absence of moisture designation indicates moisture regime is irrelevant. Asterisk (*) indicates a warm-humid location.
washington
 
 
5B Adams
4C Grays Harbor
4C Pierce
5B Asotin
4C Island
4C San Juan
5B Benton
4C Jefferson
4C Skagit
5B Chelan
4C King
5B Skamania
4C Clallam
4C Kitsap
4C Snohomish
4C Clark
5B Kittitas
5B Spokane
5B Columbia
5B Klickitat
5B Stevens
4C Cowlitz
4C Lewis
4C Thurston
5B Douglas
5B Lincoln
4C Wahkiakum
5B Ferry
4C Mason
5B Walla Walla
5B Franklin
5B Okanogan
4C Whatcom
5B Garfield
4C Pacific
5B Whitman
5B Grant
5B Pend Oreille
5B Yakima
[Statutory Authority: RCW 19.27A.025, 19.27A.045, and 19.27.074. WSR 13-23-096, § 51-11R-30100, filed 11/20/13, effective 4/1/14. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30100, filed 2/1/13, effective 7/1/13.]



PDF51-11R-30200

Section R302—Design conditions.

R302.1 Interior design conditions. The interior design temperatures used for heating and cooling load calculations shall be a maximum of 72°F (22°C) for heating and minimum of 75°F (24°C) for cooling.
R302.2 Exterior design conditions. The heating or cooling outdoor design temperatures shall be selected from Appendix C.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30200, filed 2/1/13, effective 7/1/13.]



PDF51-11R-30300

Section R303—Materials, systems and equipment.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30300, filed 2/1/13, effective 7/1/13.]



PDF51-11R-30310

Section R303.1Identification.

R303.1 Identification. Materials, systems and equipment shall be identified in a manner that will allow a determination of compliance with the applicable provisions of this code.
R303.1.1 Building thermal envelope insulation. An R-value identification mark shall be applied by the manufacturer to each piece of building thermal envelope insulation 12 inches (305 mm) or greater in width. Alternately, the insulation installers shall provide a certification listing the type, manufacturer and R-value of insulation installed in each element of the building thermal envelope. For blown or sprayed insulation (fiberglass and cellulose), the initial installed thickness, settled thickness, settled R-value, installed density, coverage area and number of bags installed shall be listed on the certification. For sprayed polyurethane foam (SPF) insulation, the installed thickness of the areas covered and R-value of installed thickness shall be listed on the certification. For insulated siding, the R-value shall be labeled on the product's package and shall be listed on the certification. The insulation installer shall sign, date and post the certification in a conspicuous location on the job site.
R303.1.1.1 Blown or sprayed roof/ceiling insulation. The thickness of blown-in or sprayed roof/ceiling insulation (fiberglass or cellulose) shall be written in inches (mm) on markers that are installed at least one for every 300 square feet (28 m2) throughout the attic space. The markers shall be affixed to the trusses or joists and marked with the minimum initial installed thickness with numbers a minimum of 1 inch (25 mm) in height. Each marker shall face the attic access opening. Spray polyurethane foam thickness and installed R-value shall be listed on certification provided by the insulation installer.
R303.1.2 Insulation mark installation. Insulating materials shall be installed such that the manufacturer's R-value mark is readily observable upon inspection.
R303.1.3 Fenestration product rating.U-factors of fenestration products (windows, doors and skylights) shall be determined in accordance with NFRC 100.
EXCEPTION:
Where required, garage door U-factors shall be determined in accordance with either NFRC 100 or ANSI/DASMA 105.
U-factors shall be determined by an accredited, independent laboratory, and labeled and certified by the manufacturer.
Products lacking such a labeled U-factor shall be assigned a default U-factor from Table R303.1.3(1), R303.1.3(2) or R303.1.3(4). The solar heat gain coefficient (SHGC) and visible transmittance (VT) of glazed fenestration products (windows, glazed doors and skylights) shall be determined in accordance with NFRC 200 by an accredited, independent laboratory, and labeled and certified by the manufacturer. Products lacking such a labeled SHGC or VT shall be assigned a default SHGC or VT from Table R303.1.3(3).
EXCEPTIONS:
1. Units without NFRC ratings produced by a small business may be assigned default U-factors from Table R303.1.3(5) for vertical fenestration.
 
2. Owner-built, nonoperable wood frame window consisting of a double pane unit with low-e (E = 0.04 or less), 1/2-inch air space with argon fill.
R303.1.4 Insulation product rating. The thermal resistance (R-value) of insulation shall be determined in accordance with the U.S. Federal Trade Commission R-value rule (C.F.R. Title 16, Part 460) in units of h × ft2 × °F/Btu at a mean temperature of 75°F (24°C).
R303.1.4.1 Insulated siding. The thermal resistance (R-value) of insulated siding shall be determined in accordance with ASTM C1363. Installation for testing shall be in accordance with the manufacturer's installation instructions.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-30310, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30310, filed 2/1/13, effective 7/1/13.]



PDF51-11R-30311

Table R303.1.3(1)Default glazed fenestration U-factor.

TABLE R303.1.3(1)
DEFAULT GLAZED FENESTRATION U-FACTOR
FRAME TYPE
SINGLE PANE
DOUBLE PANE
 
Metal
1.20
0.80
SKYLIGHT
Metal with Thermal Breaka
1.10
0.65
See Table R303.1.3(4)
Nonmetal or Metal Clad
0.95
0.55
 
Glazed Block
0.60
a
Metal Thermal Break = A metal thermal break framed window shall incorporate the following minimum design characteristics:
 
1) The thermal conductivity of the thermal break material shall be not more than 3.6 Btu-in/h/ft2/°F;
 
2) The thermal break material must produce a gap in the frame material of not less than 0.210 inches; and
 
3) All metal framing members of the products exposed to interior and exterior air shall incorporate a thermal break meeting the criteria in a) and b) above.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30311, filed 2/1/13, effective 7/1/13.]



PDF51-11R-30312

Table R303.1.3(2)Default door U-factors.

TABLE R303.1.3(2)
DEFAULT DOOR U-FACTORS
Door Type
No
Glazed
Fenestration
Single
Glazing
Double
Glazing
with 1/4 in.
Airspace
Double
Glazing
with 1/2
in.
Airspace
Double
Glazing
with
e = 0.10,
1/2 in.
Argon
SWINGING DOORS (Rough opening - 38 in. x 82 in.)
Slab Doors
 
 
 
 
 
Wood slab in wood framea
0.46
 
 
 
 
 
6% glazed fenestration (22 in. x 8 in. lite)
-
0.48
0.47
0.46
0.44
 
25% glazed fenestration (22 in. x 36 in. lite)
-
0.58
0.48
0.46
0.42
 
45% glazed fenestration (22 in. x 64 in. lite)
-
0.69
0.49
0.46
0.39
 
More than 50% glazed fenestration
Use Table R303.1.3(1)
Insulated steel slab with wood edge in wood framea
0.16
 
 
 
 
 
6% glazed fenestration (22 in. x 8 in. lite)
-
0.21
0.20
0.19
0.18
 
25% glazed fenestration (22 in. x 36 in. lite)
-
0.39
0.28
0.26
0.23
 
45% glazed fenestration (22 in. x 64 in. lite)
-
0.58
0.38
0.35
0.26
 
More than 50% glazed fenestration
Use Table R303.1.3(1)
Foam insulated steel slab with metal edge in steel frameb
0.37
 
 
 
 
 
6% glazed fenestration (22 in. x 8 in. lite)
-
0.44
0.42
0.41
0.39
 
25% glazed fenestration (22 in. x 36 in. lite)
-
0.55
0.50
0.48
0.44
 
45% glazed fenestration (22 in. x 64 in. lite)
-
0.71
0.59
0.56
0.48
 
More than 50% glazed fenestration
Use Table R303.1.3(1)
Cardboard honeycomb slab with metal edge in steel frameb
0.61
 
 
 
 
Style and Rail Doors
 
 
 
 
 
Sliding glass doors/French doors
Use Table R303.1.3(1)
Site-Assembled Style and Rail Doors
Aluminum in aluminum frame
-
1.32
0.99
0.93
0.79
Aluminum in aluminum frame with thermal break
-
1.13
0.80
0.74
0.63
Note:
Appendix A Tables A107.1(2) through A107.1(4) may also be used if applicable.
 
a
Thermally broken sill (add 0.03 for nonthermally broken sill).
 
b
Nonthermally broken sill.
[Statutory Authority: RCW 19.27A.025, 19.27A.045, 19.27.020, and 19.27.074. WSR 14-24-123, § 51-11R-30312, filed 12/3/14, effective 1/3/15. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30312, filed 2/1/13, effective 7/1/13.]



PDF51-11R-30313

Table R303.1.3(3)Default glazed fenestration SHGC and VT.

TABLE R303.1.3(3)
DEFAULT GLAZED FENESTRATION SHGC AND VT
 
SINGLE GLAZED
DOUBLE GLAZED
GLAZED BLOCK
 
Clear
Tinted
Clear
Tinted
SHGC
0.8
0.7
0.7
0.6
0.6
VT
0.6
0.3
0.6
0.3
0.6
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30313, filed 2/1/13, effective 7/1/13.]



PDF51-11R-30314

Table R303.1.3(4)Default U-factors for skylights.

TABLE R303.1.3(4)
DEFAULT U-FACTORS FOR SKYLIGHTS
 
Frame Type
 
Aluminum Without
Thermal Break
Aluminum With
Thermal Break
Reinforced Vinyl/Aluminum-Clad Wood or Vinyl
Wood or Vinyl-Clad Wood/Vinyl Without Reinforcing
Fenestration Type
Single Glazing
 
 
 
 
 
glass
U-1.58
U-1.51
U-1.40
U-1.18
 
acrylic/polycarb
U-1.52
U-1.45
U-1.34
U-1.11
Double Glazing
 
 
 
 
 
air
U-1.05
U-0.89
U-0.84
U-0.67
 
argon
U-1.02
U-0.86
U-0.80
U-0.64
Double Glazing, e = 0.20
 
 
 
 
 
air
U-0.96
U-0.80
U-0.75
U-0.59
 
argon
U-0.91
U-0.75
U-0.70
U-0.54
Double Glazing, e = 0.10
 
 
 
 
 
air
U-0.94
U-0.79
U-0.74
U-0.58
 
argon
U-0.89
U-0.73
U-0.68
U-0.52
Double Glazing, e = 0.05
 
 
 
 
 
air
U-0.93
U-0.78
U-0.73
U-0.56
 
argon
U-0.87
U-0.71
U-0.66
U-0.50
Triple Glazing
 
 
 
 
 
air
U-0.90
U-0.70
U-0.67
U-0.51
 
argon
U-0.87
U-0.69
U-0.64
U-0.48
Triple Glazing, e = 0.20
 
 
 
 
 
air
U-0.86
U-0.68
U-0.63
U-0.47
 
argon
U-0.82
U-0.63
U-0.59
U-0.43
Triple Glazing, e = 0.20 on 2 surfaces
 
 
 
 
 
air
U-0.82
U-0.64
U-0.60
U-0.44
 
argon
U-0.79
U-0.60
U-0.56
U-0.40
Triple Glazing, e  =  0.10 on 2 surfaces
 
 
 
 
 
air
U-0.81
U-0.62
U-0.58
U-0.42
 
argon
U-0.77
U-0.58
U-0.54
U-0.38
Quadruple Glazing, e = 0.10 on 2 surfaces
 
 
 
 
 
air
U-0.78
U-0.59
U-0.55
U-0.39
 
argon
U-0.74
U-0.56
U-0.52
U-0.36
 
krypton
U-0.70
U-0.52
U-0.48
U-0.32
Notes for Table R303.1.3(4)
1.
U-factors are applicable to both glass and plastic, flat and domed units, all spacers and gaps.
2.
Emissivities shall be less than or equal to the value specified.
3.
Gap fill shall be assumed to be air unless there is a minimum of 90% argon or krypton.
4.
Aluminum frame with thermal break is as defined in footnote 1 to Table R303.1.3(1).
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30314, filed 2/1/13, effective 7/1/13.]



PDF51-11R-30315

Table R303.1.3(5)Small business compliance default table.

TABLE R303.1.3(5)
SMALL BUSINESS COMPLIANCE TABLE
DEFAULT U-FACTORS FOR VERTICAL FENESTRATION
Vertical Fenestration Description
Frame Type
Any Frame
Aluminum
Thermal Break2
Wood/Vinyl/
Fiberglass
Panes
Low-e1
Spacer
Fill
Double3
A
Any
Argon
0.48
0.41
0.32
 
B
Any
Argon
0.46
0.39
0.30
 
C
Any
Argon
0.44
0.37
0.28
 
C
High
Performance
Argon
0.42
0.35
Deemed to
comply5
Triple4
A
Any
Air
0.50
0.44
0.26
 
B
Any
Air
0.45
0.39
0.22
 
C
Any
Air
0.41
0.34
0.20
 
Any double low-e
Any
Air
0.35
0.32
0.18
1
Low-eA (emissivity) shall be 0.24 to 0.16.
 
Low-eB (emissivity) shall be 0.15 to 0.08.
 
Low-eC (emissivity) shall be 0.07 or less.
2
Aluminum Thermal Break = An aluminum thermal break framed window shall incorporate the following minimum design characteristics:
a)
The thermal conductivity of the thermal break material shall be not more than 3.6 Btu-in/h/ft2/°F;
b)
The thermal break material must produce a gap in the frame material of not less than 0.210 inches; and
c)
All metal framing members of the products exposed to interior and exterior air shall incorporate a thermal break meeting the criteria in a and b above.
3
A minimum air space of 0.375 inches between panes of glass is required for double glazing.
4
A minimum air space of 0.25 inches between panes of glass is required for triple glazing.
5
Deemed to comply glazing shall not be used for performance compliance.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30315, filed 2/1/13, effective 7/1/13.]



PDF51-11R-30320

Section R303.2—Installation.

R303.2 Installation. All materials, systems and equipment shall be installed in accordance with the manufacturer's installation instructions and the International Building Code or International Residential Code, as applicable.
R303.2.1 Protection of exposed foundation insulation. Insulation applied to the exterior of basement walls, crawlspace walls and the perimeter of slab-on-grade floors shall have a rigid, opaque and weather-resistant protective covering to prevent the degradation of the insulation's thermal performance. The protective covering shall cover the exposed exterior insulation and extend a minimum of 6 inches (153 mm) below grade.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30320, filed 2/1/13, effective 7/1/13.]



PDF51-11R-30330

Section R303.3—Maintenance information.

R303.3 Maintenance information. Maintenance instructions shall be furnished for equipment and systems that require preventive maintenance. Required regular maintenance actions shall be clearly stated and incorporated on a readily accessible label. The label shall include the title or publication number for the operation and maintenance manual for that particular model and type of product.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30330, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40000

Chapter 4 [RE]—Residential energy efficiency.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40000, filed 2/1/13, effective 7/1/13.]
Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency.



PDF51-11R-40100

Section R401General.

R401.1 Scope. This chapter applies to residential buildings.
R401.2 Compliance. Projects shall comply with one of the following:
1. Sections R401 through R404.
2. Section R405 and the provisions of Sections R401 through R404 labeled "Mandatory."
In addition, dwelling units and sleeping units in a residential building shall comply with Section R406.
R401.3 Certificate (Mandatory). A permanent certificate shall be completed by the builder or registered design professional and posted on a wall in the space where the furnace is located, a utility room, or an approved location inside the building. When located on an electrical panel, the certificate shall not cover or obstruct the visibility of the circuit directory label, service disconnect label, or other required labels. The certificate shall list the predominant R-values of insulation installed in or on ceiling/roof, walls, foundation (slab, below-grade wall, and/or floor) and ducts outside conditioned spaces; U-factors for fenestration and the solar heat gain coefficient (SHGC) of fenestration, and the results from any required duct system and building envelope air leakage testing done on the building. Where there is more than one value for each component, the certificate shall list the value covering the largest area. The certificate shall list the types and efficiencies of heating, cooling and service water heating equipment. Where a gas-fired unvented room heater, electric furnace, or baseboard electric heater is installed in the residence, the certificate shall list "gas-fired unvented room heater," "electric furnace" or "baseboard electric heater," as appropriate. An efficiency shall not be listed for gas-fired unvented room heaters, electric furnaces or electric baseboard heaters.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40100, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40100, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40200

Section R402—Building thermal envelope.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40200, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40210

Section R402.1General.

R402.1 General (Prescriptive). The building thermal envelope shall meet the requirements of Sections R402.1.1 through R402.1.5.
EXCEPTION:
The following buildings, or portions thereof, separated from the remainder of the building by building thermal envelope assemblies complying with this code shall be exempt from the building thermal envelope provisions of this code.
 
1. Those with a peak design rate of energy usage less than 3.4 Btu/h ft2 (10.7 W/m2) or 1.0 watt/ft2 of floor area for space conditioning purposes.
 
2. Those that do not contain conditioned space.
 
3. Greenhouses isolated from any conditioned space and not intended for occupancy.
R402.1.1 Insulation and fenestration criteria. The building thermal envelope shall meet the requirements of Table R402.1.1 based on the climate zone specified in Chapter 3.
R402.1.2 R-value computation. Insulation material used in layers, such as framing cavity insulation or continuous insulation, shall be summed to compute the corresponding component R-value. The manufacturer's settled R-value shall be used for blown insulation. Computed R-values shall not include an R-value for other building materials or air films. Where insulated siding is used for the purpose of complying with the continuous insulation requirements of Table R402.1.1, the manufacturer must supply an ICC Report that the R-factor has been certified, or use R-5 per inch for extruded polystyrene, and R-6 per inch for polyisocyanurate rigid insulation.
R402.1.3 U-factor alternative. An assembly with a U-factor equal to or less than that specified in Table R402.1.3 shall be permitted as an alternative to the R-value in Table R402.1.1.
R402.1.4 Total UA alternative. If the total building thermal envelope UA (sum of U-factor times assembly area) is less than or equal to the total UA resulting from using the U-factors in Table R402.1.3 (multiplied by the same assembly area as in the proposed building), the building shall be considered in compliance with Table R402.1.1. The U-factors for typical construction assemblies are included in Appendix A in chapter 51-11C WAC. These values shall be used for all calculations. Where proposed construction assemblies are not represented in Appendix A, values shall be calculated in accordance with the ASHRAE Handbook of Fundamentals using the framing factors listed in Appendix A where applicable and shall include the thermal bridging effects of framing materials. The SHGC requirements shall be met in addition to UA compliance. When using REScheck, the U-factors calculated by the software based on component R-value descriptions are acceptable. For the base building UA calculation, the maximum glazing area is 15% of the floor area.
R402.1.5 Vapor retarder. Wall assemblies in the building thermal envelope shall comply with the vapor retarder requirements of Section R702.7 of the International Residential Code or Section 1405.3 of the International Building Code, as applicable.
[Statutory Authority: RCW 19.27A.025, 19.27A.045, 19.27A.160, and 19.27.074. WSR 17-10-063, § 51-11R-40210, filed 5/2/17, effective 6/2/17. Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40210, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40210, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40211

Table R402.1.1Insulation and fenestration requirements by component.

TABLE R402.1.1
INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENTa
Climate Zone
Fenestration
U-Factorb
Skylightb
U-Factor
Glazed
Fenestration SHGCb, e
Ceiling
R-Valuek
Wood Frame Wallg, m, n
R-Value
Mass Wall
R-Valuei
Floor
R-Value
Below-
Gradec, m Wall R-Value
Slabd
R-Value & Depth
5 and Marine 4
0.30
0.50
NR
49
21 int
21/ 21
30
10/15/
21int+TB
10, 2 ft
For SI:
1 foot = 304.8 mm, ci = continuous insulation, int = intermediate framing.
 
aR-values are minimums. U-factors and SHGC are maximums. When insulation is installed in a cavity which is less than the label or design thickness of the insulation, the compressed R-value of the insulation from Appendix Table A101.4 shall not be less than the R-value specified in the table.
 
b The fenestration U-factor column excludes skylights. The SHGC column applies to all glazed fenestration.
 
c "10/15/21+TB" means R-10 continuous insulation on the exterior of the wall, or R-15 on the continuous insulation on the interior of the wall, or R-21 cavity insulation plus a thermal break between the slab and the basement wall at the interior of the basement wall. "10/15/21+TB" shall be permitted to be met with R-13 cavity insulation on the interior of the basement wall plus R-5 continuous insulation on the interior or exterior of the wall. "TB" means thermal break between floor slab and basement wall.
 
d R-10 continuous insulation is required under heated slab on grade floors. See R402.2.9.1.
 
e There are no SHGC requirements in the Marine Zone.
 
f Reserved.
 
g Reserved.
 
h Reserved.
 
i The second R-value applies when more than half the insulation is on the interior of the mass wall.
 
j Reserved.
 
k For single rafter- or joist-vaulted ceilings, the insulation may be reduced to R-38.
 
l Reserved.
 
m Int. (intermediate framing) denotes standard framing 16 inches on center with headers insulated with a minimum of R-10 insulation.
 
n Log and solid timber walls with a minimum average thickness of 3.5 inches are exempt from this insulation requirement.
[Statutory Authority: RCW 19.27A.025, 19.27A.045, 19.27A.160, and 19.27.074. WSR 17-10-063, § 51-11R-40211, filed 5/2/17, effective 6/2/17. Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40211, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.025, 19.27A.045, and 19.27.074. WSR 13-20-121, § 51-11R-40211, filed 10/1/13, effective 11/1/13. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40211, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40213

Table R402.1.3Equivalent U-factors.

TABLE R402.1.3
EQUIVALENT U-FACTORSa
Climate Zone
Fenestration
U-Factor
Skylight
U-Factor
Ceiling
U-Factor
Frame Wall
U-Factor
Mass Wall
U-Factorb
Floor
U-Factor
Below-
Grade Wall U-Factor
5 and Marine 4
0.30
0.50
0.026
0.056
0.056
0.029
0.042
a Nonfenestration U-factors shall be obtained from measurement, calculation or an approved source or as specified in Section R402.1.3.
b Reserved.
c Reserved.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40213, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40213, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40220

Section R402.2Specific insulation requirements.

R402.2 Specific insulation requirements (Prescriptive). In addition to the requirements of Section R402.1, insulation shall meet the specific requirements of Sections R402.2.1 through R402.2.11.
R402.2.1 Ceilings with attic spaces. Where Section R402.1.1 would require R-49 in the ceiling, installing R-38 over 100 percent of the ceiling area requiring insulation shall be deemed to satisfy the requirement for R-49 wherever the full height of uncompressed R-38 insulation extends over the wall top plate at the eaves. This reduction shall not apply to the U-factor alternative approach in Section R402.1.3 and the total UA alternative in Section R402.1.4.
R402.2.1.1 Loose insulation in attic spaces. Open-blown or poured loose fill insulation may be used in attic spaces where the slope of the ceiling is not more than 3 feet in 12 and there is at least 30 inches of clear distance from the top of the bottom chord of the truss or ceiling joist to the underside of the sheathing at the roof ridge.
R402.2.3 Eave baffle. For air permeable insulations in vented attics, a baffle shall be installed adjacent to soffit and eave vents. Baffles shall maintain an opening equal or greater than the size of the vent. The baffle shall extend over the top of the attic insulation. The baffle shall be permitted to be any solid material.
R402.2.4 Access hatches and doors. Access doors from conditioned spaces to unconditioned spaces (e.g., attics and crawl spaces) shall be weatherstripped and insulated to a level equivalent to the insulation on the surrounding surfaces. Access shall be provided to all equipment that prevents damaging or compressing the insulation. A wood framed or equivalent baffle or retainer is required to be provided when loose fill insulation is installed, the purpose of which is to prevent the loose fill insulation from spilling into the living space when the attic access is opened, and to provide a permanent means of maintaining the installed R-value of the loose fill insulation.
EXCEPTION:
Vertical doors that provide access from conditioned to unconditioned spaces shall be permitted to meet the fenestration requirements of Table R402.1.1.
R402.2.5 Mass walls. Mass walls for the purposes of this chapter shall be considered above-grade walls of concrete block, concrete, insulated concrete form (ICF), masonry cavity, brick (other than brick veneer), earth (adobe, compressed earth block, rammed earth) and solid timber/logs, or any other walls having a heat capacity greater than or equal to 6 Btu/ft2 x °F (123 kJ/m2 x K).
R402.2.6 Steel-frame ceilings, walls, and floors. Steel-frame ceilings, walls, and floors shall meet the U-factor requirements of Table R402.1.3.
R402.2.7 Floors. Floor framing cavity insulation shall be installed to maintain permanent contact with the underside of the subfloor decking. Insulation supports shall be installed so spacing is no more than 24 inches on center. Foundation vents shall be placed so that the top of the vent is below the lower surface of the floor insulation.
EXCEPTIONS:
1. The floor framing cavity insulation shall be permitted to be in contact with the topside of sheathing or continuous insulation installed on the bottom side of floor framing where combined with insulation that meets or exceeds the minimum Wood Frame Wall R-value in Table R402.1.1 and extends from the bottom to the top of all perimeter floor framing members.
 
2. When foundation vents are not placed so that the top of the vent is below the lower surface of the floor insulation, a permanently attached baffle shall be installed at an angle of 30° from horizontal, to divert air flow below the lower surface of the floor insulation.
 
3. Substantial contact with the surface being insulated is not required in enclosed floor/ceiling assemblies containing ducts where full R-value insulation is installed between the duct and the exterior surface.
R402.2.8 Below-grade walls. Below-grade exterior wall insulation used on the exterior (cold) side of the wall shall extend from the top of the below-grade wall to the top of the footing and shall be approved for below-grade use. Above-grade insulation shall be protected. Insulation used on the interior (warm) side of the wall shall extend from the top of the below-grade wall to the below-grade floor level and shall include R-5 rigid board providing a thermal break between the concrete wall and the slab.
R402.2.9 Slab-on-grade floors. The minimum thermal resistance (R-value) of the insulation around the perimeter of unheated or heated slab-on-grade floors shall be as specified in Table C402.1.1. The insulation shall be placed on the outside of the foundation or on the inside of the foundation wall. The insulation shall extend downward from the top of the slab for a minimum distance as shown in the table or to the top of the footing, whichever is less, or downward to at least the bottom of the slab and then horizontally to the interior or exterior for the total distance shown in the table. A two-inch by two-inch (maximum) pressure treated nailer may be placed at the finished floor elevation for attachment of interior finish materials. Insulation extending away from the building shall be protected by pavement or by a minimum of 10 inches (254 mm) of soil.
R402.2.9.1 Heated slab-on-grade floors (Mandatory). The entire area of a heated slab-on-grade floor shall be thermally isolated from the soil with a minimum of R-10 insulation. The insulation shall be an approved product for its intended use. If a soil gas control system is present below the heated slab-on-grade floor, which results in increased convective flow below the heated slab-on-grade floor, the heated slab-on-grade floor shall be thermally isolated from the sub-slab gravel layer. R-10 heated slab-on-grade floor insulation is required for all compliance paths.
R402.2.10 Reserved.
R402.2.11 Masonry veneer. Insulation shall not be required on the horizontal portion of the foundation that supports a masonry veneer.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40220, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40220, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40230

Section R402.3Fenestration.

R402.3 Fenestration (Prescriptive). In addition to the requirements of Section R402, fenestration shall comply with Sections R402.3.1 through R402.3.5.
R402.3.1 U-factor. An area-weighted average of fenestration products shall be permitted to satisfy the U-factor requirements.
R402.3.2 Glazed fenestration SHGC. An area-weighted average of fenestration products more than 50 percent glazed shall be permitted to satisfy the SHGC requirements.
R402.3.3 Glazed fenestration exemption. Up to 15 square feet (1.4 m2) of glazed fenestration per dwelling unit shall be permitted to be exempt from U-factor and SHGC requirements in Section R402.1.1. This exemption shall not apply to the U-factor alternative approach in Section R402.1.3 and the total UA alternative in Section R402.1.4.
R402.3.4 Opaque door exemption. One side-hinged opaque door assembly up to 24 square feet (2.22 m2) in area is exempted from the U-factor requirement in Section R402.1.1. This exemption shall not apply to the U-factor alternative approach in Section R402.1.3 and the total UA alternative in Section R402.1.4.
R402.3.5 Reserved.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40230, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40230, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40240

Section R402.4Air leakage.

R402.4 Air leakage (Mandatory). The building thermal envelope shall be constructed to limit air leakage in accordance with the requirements of Sections R402.4.1 through R402.4.4.
R402.4.1 Building thermal envelope. The building thermal envelope shall comply with Sections R402.4.1.1 and R402.4.1.2. The sealing methods between dissimilar materials shall allow for differential expansion and contraction.
R402.4.1.1 Installation. The components of the building thermal envelope as listed in Table R402.4.1.1 shall be installed in accordance with the manufacturer's instructions and the criteria listed in Table R402.4.1.1, as applicable to the method of construction. Where required by the code official, an approved third party shall inspect all components and verify compliance.
R402.4.1.2 Testing. The building or dwelling unit shall be tested and verified as having an air leakage rate of not exceeding 5 air changes per hour. Testing shall be conducted with a blower door at a pressure of 0.2 inches w.g. (50 Pascals). Where required by the code official, testing shall be conducted by an approved third party. A written report of the results of the test shall be signed by the party conducting the test and provided to the code official. Testing shall be performed at any time after creation of all penetrations of the building thermal envelope. Once visual inspection has confirmed sealing (see Table R402.4.1.1), operable windows and doors manufactured by small business shall be permitted to be sealed off at the frame prior to the test.
During testing:
1. Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed, beyond the intended weatherstripping or other infiltration control measures;
2. Dampers including exhaust, intake, makeup air, backdraft and flue dampers shall be closed, but not sealed beyond intended infiltration control measures;
3. Interior doors, if installed at the time of the test, shall be open, access hatches to conditioned crawl spaces and conditioned attics shall be open;
4. Exterior openings for continuous ventilation systems and heat recovery ventilators shall be closed and sealed;
5. Heating and cooling systems, if installed at the time of the test, shall be turned off; and
6. Supply and return registers, if installed at the time of the test, shall be fully open.
EXCEPTIONS:
1. Additions less than 500 square feet of conditioned floor area.
 
2. Additions tested with the existing home having a combined maximum air leakage rate of 7 air changes per hour. To qualify for this exception, the date of construction of the existing house must be prior to the 2009 Washington State Energy Code.
R402.4.2 Fireplaces. New wood-burning fireplaces shall have tight-fitting flue dampers or doors, and outdoor combustion air. When using tight-fitting doors on factory-built fireplaces listed and labeled in accordance with UL 127, the doors shall be tested and listed for the fireplace. Where using tight-fitting doors on masonry fireplaces, the doors shall be listed and labeled in accordance with UL 907.
R402.4.3 Air leakage of fenestration. Windows, skylights and sliding glass doors shall have an air infiltration rate of no more than 0.3 cfm per square foot (1.5 L/s/m2), and swinging doors no more than 0.5 cfm per square foot (2.6 L/s/m2), when tested according to NFRC 400 or AAMA/WDMA/CSA 101/I.S.2/A440 by an accredited, independent laboratory and listed and labeled by the manufacturer.
EXCEPTIONS:
1. Field-fabricated fenestration products (windows, skylights and doors).
 
2. Custom exterior fenestration products manufactured by a small business provided they meet the applicable provisions of Chapter 24 of the International Building Code. Once visual inspection has confirmed the presence of a gasket, operable windows and doors manufactured by small business shall be permitted to be sealed off at the frame prior to the test.
R402.4.4Combustion air openings. In Climate Zones 3 through 8, where open combustion air ducts provide combustion air to open combustion, space conditioning fuel burning appliances, the appliances and combustion air openings shall be located outside of the building thermal envelope, or enclosed in a room isolated from inside the thermal envelope. Such rooms shall be sealed and insulated in accordance with the envelope requirements of Table R402.1.1, where the walls, floors and ceilings shall meet the minimum of the below-grade wall R-value requirement. The door into the room shall be fully gasketed and any water lines and ducts in the room insulated in accordance with Section R403. The combustion air duct shall be insulated where it passes through conditioned space to a minimum of R-8.
EXCEPTIONS:
1. Direct vent appliances with both intake and exhaust pipes installed continuous to the outside.
 
2. Fireplaces and stoves complying with Section R402.4.2 and Section R1006 of the International Residential Code.
R402.4.5 Recessed lighting. Recessed luminaires installed in the building thermal envelope shall be Type IC-rated and certified under ASTM E283 as having an air leakage rate not more than 2.0 cfm (0.944 L/s) when tested at a 1.57 psf (75 Pa) pressure differential and shall have a label attached showing compliance with this test method. All recessed luminaires shall be sealed with a gasket or caulk between the housing and the interior wall or ceiling covering.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40240, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.025, 19.27A.045, 19.27.020, and 19.27.074. WSR 14-24-123, § 51-11R-40240, filed 12/3/14, effective 1/3/15. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40240, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40241

Table R402.4.1.1Air barrier and insulation installation.

TABLE R402.4.1.1
AIR BARRIER AND INSULATION INSTALLATION
COMPONENT
AIR BARRIER CRITERIAa
INSULATION CRITERIAa
General requirements
A continuous air barrier shall be installed in the building envelope.
Air-permeable insulation shall not be used as a sealing material.
Exterior thermal envelope contains a continuous air barrier.
Breaks or joints in the air barrier shall be sealed.
Cavity insulation installation
 
All cavities in the thermal envelope shall be filled with insulation. The density of the insulation shall be at the manufacturers' product recommendation and said density shall be maintained for all volume of each cavity. Batt type insulation will show no voids or gaps and maintain an even density for the entire cavity. Batt insulation shall be installed in the recommended cavity depth. Where an obstruction in the cavity due to services, blocking, bracing or other obstruction exists, the batt product will be cut to fit the remaining depth of the cavity. Where the batt is cut around obstructions, loose fill insulation shall be placed to fill any surface or concealed voids, and at the manufacturers' specified density. Where faced batt is used, the installation tabs must be stapled to the face of the stud. There shall be no compression to the batt at the edges of the cavity due to inset stapling installation tabs.
Insulation that upon installation readily conforms to available space shall be installed filling the entire cavity and within the manufacturers' density recommendation.
Ceiling/attic
The air barrier in any dropped ceiling/soffit shall be aligned with the insulation and any gaps in the air barrier sealed.
The insulation in any dropped ceiling/soffit shall be aligned with the air barrier.
Access openings, drop down stair or knee wall doors to unconditioned attic spaces shall be sealed.
Batt insulation installed in attic roof assemblies may be compressed at exterior wall lines to allow for required attic ventilation.
Walls
The junction of the foundation and sill plate shall be sealed. The junction of the top plate and top of exterior walls shall be sealed. Knee walls shall be sealed.
Cavities within corners and headers of frame walls shall be insulated by completely filling the cavity with a material having a thermal resistance of R-3 per inch minimum. 
Exterior thermal envelope insulation for framed walls shall be installed in substantial contact and continuous alignment with the air barrier.
Windows, skylights and doors
The space between window/door jambs and framing and skylights and framing shall be sealed.
 
Rim joists
Rim joists shall include the air barrier.
Rim joists shall be insulated.
Floors (including above garage and cantilevered floors)
The air barrier shall be installed at any exposed edge of insulation.
Floor framing cavity insulation shall be installed to maintain permanent contact with the underside of subfloor decking or floor framing cavity insulation shall be permitted to be in contact with the topside of sheathing or continuous insulation installed on the underside of floor framing and extend from the bottom to the top of all perimeter floor framing members.
Crawl space walls
Exposed earth in unvented crawl spaces shall be covered with a Class I, black vapor retarder with overlapping joints taped.
Where provided instead of floor insulation, insulation shall be permanently attached to the crawlspace walls.
Shafts, penetrations
Duct shafts, utility penetrations, and flue shafts opening to exterior or unconditioned space shall be sealed.
 
Narrow cavities
 
Batts in narrow cavities shall be cut to fit and installed to the correct density without any voids or gaps or compression, or narrow cavities shall be filled by insulation that on installation readily conforms to the available cavity space.
Garage separation
Air sealing shall be provided between the garage and conditioned spaces.
 
Recessed lighting
Recessed light fixtures installed in the building thermal envelope shall be sealed to the drywall.
Recessed light fixtures installed in the building thermal envelope shall be air tight and IC rated.
Plumbing and wiring
 
Batt insulation shall be cut neatly to fit around wiring and plumbing in exterior walls. There shall be no voids or gaps or compression where cut to fit. Insulation that on installation readily conforms to available space shall extend behind piping and wiring.
Shower/tub on exterior wall
The air barrier installed at exterior walls adjacent to showers and tubs shall separate them from the showers and tubs.
Exterior walls adjacent to showers and tubs shall be insulated.
Electrical/phone box on exterior wall
The air barrier shall be installed behind electrical or communication boxes or air sealed boxes shall be installed.
 
HVAC register boots
HVAC register boots that penetrate building thermal envelope shall be sealed to the subfloor or drywall.
 
Concealed sprinklers
When required to be sealed, concealed fire sprinklers shall only be sealed in a manner that is recommended by the manufacturer. Caulking or other adhesive sealants shall not be used to fill voids between fire sprinkler cover plates and walls or ceilings.
 
IC = insulation contact.
a In addition, inspection of log walls shall be in accordance with the provisions of ICC-400.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40241, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40241, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40250

Section R402.5Maximum fenestration U-factor and SHGC.

R402.5 Maximum fenestration U-factor (Mandatory). The area-weighted average maximum fenestration U-factor permitted using tradeoffs from Section R402.1.4 or R405 shall be 0.48 for vertical fenestration, and 0.75 for skylights.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40250, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40250, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40300

Section R403—Systems.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40300, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40310

Section R403.1Controls.

R403.1 Controls (Mandatory). At least one thermostat shall be provided for each separate heating and cooling system.
R403.1.1 Programmable thermostat. Where the primary heating system is a forced-air furnace, at least one thermostat per dwelling unit shall be capable of controlling the heating and cooling system on a daily schedule to maintain different temperature set points at different times of the day. The thermostat shall allow for, at a minimum, a 5-2 programmable schedule (weekdays/weekends) and be capable of providing at least two programmable setback periods per day. This thermostat shall include the capability to set back or temporarily operate the system to maintain zone temperatures down to 55°F (13°C) or up to 85°F (29°C). The thermostat shall initially be programmed by the manufacturer with a heating temperature set point no higher than 70°F (21°C) and a cooling temperature set point no lower than 78°F (26°C). The thermostat and/or control system shall have an adjustable deadband of not less than 10°F.
EXCEPTIONS:
1. Systems controlled by an occupant sensor that is capable of shutting the system off when no occupant is sensed for a period of up to 30 minutes.
 
2. Systems controlled solely by a manually operated timer capable of operating the system for no more than two hours.
R403.1.2 Heat pump supplementary heat (Mandatory). Unitary air cooled heat pumps shall include controls that minimize supplemental heat usage during start-up, set-up, and defrost conditions. These controls shall anticipate need for heat and use compression heating as the first stage of heat. Controls shall indicate when supplemental heating is being used through visual means (e.g., LED indicators). Heat pumps equipped with supplementary heaters shall be installed with controls that prevent supplemental heater operation above 40°F. At final inspection the auxiliary heat lock out control shall be set to 35°F or less.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40310, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40310, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40315

Section R403.2Hot water boiler.

R403.2 Hot water boiler outdoor temperature setback. Hot water boilers that supply heat to the building through one- or two-pipe heating systems shall have an outdoor temperature setback control that lowers the boiler water temperature based on the outdoor temperature.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40315, filed 1/6/16, effective 7/1/16.]



PDF51-11R-40320

Section R403.3Ducts.

R403.3 Ducts. Ducts and air handlers shall be in accordance with Sections R403.3.1 through R403.3.5.
R403.3.1 Insulation (Prescriptive). Ducts outside the building thermal envelope shall be insulated to a minimum of R-8. Ducts within a concrete slab or in the ground shall be insulated to R-10 with insulation designed to be used below grade.
EXCEPTION:
Ducts or portions thereof located completely inside the building thermal envelope. Ducts located in crawl spaces do not qualify for this exception.
R403.3.2 Sealing (Mandatory). Ducts, air handlers, and filter boxes shall be sealed. Joints and seams shall comply with either the International Mechanical Code or International Residential Code, as applicable.
EXCEPTIONS:
1. Air-impermeable spray foam products shall be permitted to be applied without additional joint seals.
 
2. For ducts having a static pressure classification of less than 2 inches of water column (500 Pa), additional closure systems shall not be required for continuously welded joints and seams, and locking-type joints and seams of other than the snap-lock and button-lock types.
R403.3.2.1 Sealed air handler. Air handlers shall have a manufacturer's designation for an air leakage of no more than 2 percent of the design air flow rate when tested in accordance with ASHRAE 193.
R403.3.3 Duct testing (Mandatory). Ducts shall be leak tested in accordance with WSU RS-33, using the maximum duct leakage rates specified.
EXCEPTION:
The total leakage or leakage to the outdoors test is not required for ducts and air handlers located entirely within the building thermal envelope. For forced air ducts, a maximum of 10 linear feet of return ducts and 5 linear feet of supply ducts may be located outside the conditioned space. All metallic ducts located outside the conditioned space must have both transverse and longitudinal joints sealed with mastic. If flex ducts are used, they cannot contain splices. Flex duct connections must be made with nylon straps and installed using a plastic strapping tensioning tool. Ducts located in crawl spaces do not qualify for this exception.
A written report of the results shall be signed by the party conducting the test and provided to the code official.
R403.3.4 Duct leakage (Mandatory). The total leakage of the ducts, where measured in accordance with Section R403.3.3, shall be as follows:
1. Rough-in test: Total leakage shall be less than or equal to 4 cfm (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across the system, including the manufacturer's air handler enclosure. All registers shall be taped or otherwise sealed during the test. If the air handler is not installed at the time of the test, total leakage shall be less than or equal to 3 cfm (85 L/min) per 100 square feet (9.29 m2) of conditioned floor area.
2. Postconstruction test: Leakage to outdoors shall be less than or equal to 4 cfm (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area or total leakage shall be less than or equal to 4 cfm (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across the entire system, including the manufacturer's air handler enclosure. All register boots shall be taped or otherwise sealed during the test.
R403.3.5 Building cavities (Mandatory). Building framing cavities shall not be used as ducts or plenums. Installation of ducts in exterior walls, floors or ceilings shall not displace required envelope insulation.
[Statutory Authority: RCW 19.27A.025, 19.27A.045, 19.27A.160, and 19.27.074. WSR 17-10-063, § 51-11R-40320, filed 5/2/17, effective 6/2/17. Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40320, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40320, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40330

Section R403.4Mechanical system piping insulation.

R403.4 Mechanical system piping insulation (Mandatory). Mechanical system piping capable of carrying fluids above 105°F (41°C) or below 55°F (13°C) shall be insulated to a minimum of R-6.
EXCEPTION:
Up to 200 feet of hydronic system piping installed within the conditioned space may be insulated with a minimum of 1/2-inch insulation with a k value of 0.28.
R403.4.1 Protection of piping insulation. Piping insulation exposed to weather shall be protected from damage, including that caused by sunlight, moisture, equipment maintenance, and wind, and shall provide shielding from solar radiation that can cause degradation of the material. Adhesive tape shall not be permitted.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40330, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40330, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40340

Section R403.5Service hot water systems.

R403.5 Service hot water systems. Energy conservation measures for service hot water systems shall be in accordance with Sections R403.5.1 through R403.5.5.
R403.5.1 Heated water circulation and temperature maintenance system (Mandatory). Heated water circulation systems shall be in accordance with Section R403.5.1.1. Heat trace temperature maintenance systems shall be in accordance with Section R403.5.1.2. Automatic controls, temperature sensors and pumps shall be accessible. Manual controls shall be readily accessible.
R403.5.1.1 Circulation systems. Heated water circulation systems shall be provided with a circulation pump. The system return pipe shall be a dedicated return pipe or a cold water supply pipe. Gravity and thermo-syphon circulation systems shall be prohibited. Controls for circulating hot water system pumps shall start the pump based on the identification of a demand for hot water within the occupancy. The controls shall automatically turn off the pump when the water in the circulation loop is at the desired temperature and when there is no demand for hot water.
R403.5.1.2 Heat trace systems. Electric heat trace systems shall comply with IEEE 515.1 or UL 515. Controls for such systems shall automatically adjust the energy input to the heat tracing to maintain the desired water temperature in the piping in accordance with the times when heated water is used in the occupancy.
R403.5.2 Demand recirculation systems. A water distribution system having one or more recirculation pumps that pump water from a heated water supply pipe back to the heated water source through a cold water supply pipe shall be a demand recirculation water system. Pumps shall have controls that comply with both of the following:
1. The control shall start the pump upon receiving a signal from the action of a user of a fixture or appliance, sensing the presence of a user of a fixture or sensing the flow of hot or tempered water to a fixture fitting or appliance.
2. The control shall limit the temperature of the water entering the cold water piping to 104ºF (40ºC).
R403.5.3 Hot water pipe insulation (Prescriptive). Insulation for hot water pipe, both within and outside the conditioned space, shall have a minimum thermal resistance (R-value) of R-3.
EXCEPTION:
Pipe insulation is permitted to be discontinuous where it passes through studs, joists or other structural members and where the insulated pipes pass other piping, conduit or vents, provided the insulation is installed tight to each obstruction.
R403.5.4 Drain water heat recovery units. Drain water heat recovery units shall comply with CSA 55.2. Drain water heat recovery units shall be in accordance with CSA 55.1. Potable water-side pressure loss of drain water heat recovery units shall be less than 3 psi (20.7 kPa) for individual units connected to one or two showers. Potable water-side pressure loss of drain water heat recovery units shall be less than 2 psi (13.8 kPa) for individual units connected to three or more showers.
R403.5.5 Electric water heater insulation. All electric water heaters in unheated spaces or on concrete floors shall be placed on an incompressible, insulated surface with a minimum thermal resistance of R-10.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40340, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.025, 19.27A.045, 19.27.020, and 19.27.074. WSR 14-24-053, § 51-11R-40340, filed 11/25/14, effective 5/1/15. Statutory Authority: RCW 19.27A.025, 19.27A.045, and 19.27.074. WSR 13-20-121, § 51-11R-40340, filed 10/1/13, effective 11/1/13. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40340, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40350

Section R403.6Mechanical ventilation.

R403.6 Mechanical ventilation (Mandatory). The building shall be provided with ventilation that meets the requirements of the International Residential Code or International Mechanical Code, as applicable, or with other approved means of ventilation. Outdoor air intakes and exhausts shall have automatic or gravity dampers that close when the ventilation system is not operating.
R403.6.1 Whole-house mechanical ventilation system fan efficacy. Mechanical ventilation system fans shall meet the efficacy requirements of Table R403.6.1.
EXCEPTION:
Where mechanical ventilation fans are integral to tested and listed HVAC equipment, they shall be powered by an electronically commutated motor.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40350, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40350, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40351

Table R403.6.1Mechanical ventilation system fan efficacy.

TABLE R403.6.1
MECHANICAL VENTILATION SYSTEM FAN EFFICACY
Fan Location
Air Flow Rate Minimum (cfm)
Minimum Efficacy (cfm/watt)
Air Flow Rate Maximum (cfm)
Range hoods
Any
2.8
Any
In-line fan
Any
2.8
Any
Bathroom, utility room
10
1.4
< 90
Bathroom, utility room
90
2.8
Any
For SI: 1 cfm = 28.3 L/min.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40351, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40351, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40360

Section R403.7Equipment sizing.

R403.7 Equipment sizing and efficiency rating (Mandatory). Heating and cooling equipment shall be sized in accordance with ACCA Manual S based on building loads calculated in accordance with ACCA Manual J or other approved heating and cooling calculation methodologies. The output capacity of heating and cooling equipment shall not be greater than that of the smallest available equipment size that exceeds the loads calculated, including allowable oversizing limits. New or replacement heating and cooling equipment shall have an efficiency rating equal to or greater than the minimum required by federal law for the geographic location where the equipment is installed.
R403.7.1 Electric resistance zone heated units. All detached one- and two-family dwellings and multiple single-family dwellings (townhouses) up to three stories in height above grade plane using electric zonal heating as the primary heat source shall install an inverter-driven ductless mini-split heat pump in the largest zone in the dwelling. Building permit drawings shall specify the heating equipment type and location of the heating system.
EXCEPTION:
Total installed heating capacity of 2 kW per dwelling unit or less.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40360, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40360, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40370

Section R403.8Systems serving multiple dwelling units.

R403.8 Systems serving multiple dwelling units (Mandatory). Systems serving multiple dwelling units shall comply with Sections C403 and C404 of the WSECCommercial Provisions in lieu of Section R403.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40370, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40370, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40380

Section R403.9Snow melt system controls.

R403.9 Snow melt system controls (Mandatory). Snow and ice-melting systems, supplied through energy service to the building, shall include automatic controls capable of shutting off the system when the pavement temperature is above 50°F, and no precipitation is falling and an automatic or manual control that will allow shutoff when the outdoor temperature is above 40°F.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40380, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40380, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40390

Section R403.10Pool and spa energy consumption.

R403.10 Pool and permanent spa energy consumption (Mandatory). Pools and permanent spas shall comply with Sections R403.10.1 through R403.10.4.2.
R403.10.1 Heaters.The electric power to heaters shall be controlled by a readily accessible on-off switch that is an integral part of the heater mounted on the exterior of the heater, or external to and within 3 feet (914 mm) of the heater. Operation of such switch shall not change the settings of the heater thermostat. Such switches shall be in addition to a circuit breaker for the power to the heater. Gas-fired heaters shall not be equipped with constant burning pilot lights.
R403.10.2 Time switches. Time switches or other control method that can automatically turn off and on according to a preset schedule shall be installed for heaters and pump motors. Heaters and pump motors that have built in time switches shall be deemed in compliance with this requirement.
EXCEPTIONS:
1. Where public health standards require 24-hour pump operation.
 
2. Pumps that operate solar- and waste-heat-recovery pool heating systems.
R403.10.3 Covers. Outdoor heated pools and outdoor permanent spas shall be provided with a vapor-retardant cover, or other approved vapor retardant means.
EXCEPTION:
Where more than 70 percent of the energy for heating, computed over an operating season, is from site-recovered energy, such as from a heat pump or solar energy source, covers or other vapor-retardant means shall not be required.
R403.10.4 Residential pool pumps. Pool pump motors may not be split-phase or capacitor start-induction run type.
R403.10.4.1 Two-speed capability.
1. Pump motors: Pool pump motors with a capacity of 1 hp or more shall have the capability of operating at two or more speeds with low speed having a rotation rate that is no more than one-half of the motor's maximum rotation rate.
2. Pump controls: Pool pump motor controls shall have the capability of operating the pool pump with at least two speeds. The default circulation speed shall be the lowest speed, with a high speed override capability being for a temporary period not to exceed one normal cycle.
R403.10.4.2 Pump operation. Circulating water systems shall be controlled so that the circulation pump(s) can be conveniently turned off, automatically or manually, when the water system is not in operation.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40390, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40390, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40391

Section R403.10Other pools and spas.

R403.11 Portable spas (Mandatory). The energy consumption of electric-powered portable spas shall be controlled by the requirements of APSP-14.
R403.12 Residential pools and permanent residential spas. Residential swimming pools and permanent residential spas that are accessory to detached one- and two-family dwellings and townhouses three stories or less in height above grade plane and that are available only to the household and its guests shall be in accordance with APSP-15.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40391, filed 1/6/16, effective 7/1/16.]



PDF51-11R-40400

Section R404—Electrical power and lighting systems.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40400, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40410

Section R404.1Lighting equipment.

R404.1 Lighting equipment (Mandatory). A minimum of 75 percent of lamps in permanently installed lighting fixtures shall be high-efficacy lamps.
R404.1.1 Lighting equipment (Mandatory). Fuel gas lighting systems shall not have continuously burning pilot lights.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40410, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40410, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40500

Section R405—Simulated performance alternative (Performance).

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40500, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40510

Section R405.1—Scope.

R405.1 Scope. This section establishes criteria for compliance using simulated energy performance analysis. Such analysis shall include heating, cooling, and service water heating energy only.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40510, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40520

Section R405.2—Mandatory requirements.

R405.2 Mandatory requirements. Compliance with this section requires that the mandatory provisions identified in Section R401.2 be met. All supply and return ducts not completely inside the building thermal envelope shall be insulated to a minimum of R-8.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40520, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40530

Section R405.3Performance-based compliance.

R405.3 Performance-based compliance. Compliance based on simulated energy performance requires that a proposed residence (proposed design) be shown to have an annual energy consumption based on site energy expressed in Btu and Btu per square foot of conditioned floor area as follows:
1. For structures less than 1,500 square feet of conditioned floor area, the annual energy consumption shall be less than or equal to 80 percent of the annual energy consumption of the standard reference design.
2. For structures 1,500 to 5,000 square feet of conditioned floor area, the annual energy consumption shall be no more than 72 percent of the standard reference design.
3. For structures over 5,000 square feet of conditioned floor area, the annual energy consumption shall be no more than 66 percent of the standard reference design.
EXCEPTION:
For structures serving Group R-2 occupancies, the annual energy consumption shall be less than or equal to 85 percent of the annual energy consumption of the standard reference design.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40530, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40530, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40540

Section R405.4Documentation.

R405.4 Documentation. Documentation of the software used for the performance design and the parameters for the building shall be in accordance with Sections R405.4.1 through R405.4.3.
R405.4.1 Compliance software tools. Documentation verifying that the methods and accuracy of the compliance software tools conform to the provisions of this section shall be provided to the code official.
R405.4.2 Compliance report. Compliance software tools shall generate a report that documents that the proposed design complies with Section R405.3.
A compliance report on the proposed design shall be submitted with the application for the building permit. Upon completion of the building, a compliance report based upon the as-built condition of the building shall be submitted to the code official before a certificate of occupancy is issued. Batch sampling of buildings to determine energy code compliance for all buildings in the batch shall be prohibited.
Compliance reports shall include information in accordance with Sections R405.4.2.1 and R405.4.2.2. Where the proposed design of a building could be built on different sites where the cardinal orientation of the building on each site is different, compliance of the proposed design for the purposes of the application for the building permit shall be based upon the worst-case orientation, worst-case configuration, worst-case building air leakage and worst-case duct leakage. Such worst-case parameters shall be used as inputs to the compliance software for energy analysis.
R405.4.2.1 Compliance report for permit application. A compliance report submitted with the application for building permit shall include all of the following:
1. Building street address, or other building site identification.
2. A statement indicating that the proposed design complies with Section R405.3.
3. An inspection checklist documenting the building component characteristics of the proposed design as indicated in Table R405.5.2(1). The inspection checklist shall show results for both the standard reference design and the proposed design with all user inputs to the compliance software to generate the results.
4. A site-specific energy analysis report that is in compliance with Section R405.3.
5. Name of the individual performing the analysis and generating the report.
6. Name and version of the compliance software tool.
R405.4.2.2 Compliance report for certificate of occupancy. A compliance report submitted for obtaining the certificate of occupancy shall include all of the following:
1. Building street address, or other building site identification.
2. A statement indicating that the as-built building complies with Section R405.3.
3. A certificate indicating that the building passes the performance matrix for code compliance and the energy saving features of the building.
4. A site-specific energy analysis report that is in compliance with Section R405.3.
5. Name of the individual performing the analysis and generating the report.
6. Name and version of the compliance software tool.
R405.4.3 Additional documentation. The code official shall be permitted to require the following documents:
1. Documentation of the building component characteristics of the standard reference design.
2. A certification signed by the builder providing the building component characteristics of the proposed design as given in Table R405.5.2(1).
3. Documentation of the actual values used in the software calculations for the proposed design.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40540, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40540, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40550

Section R405.5—Calculation procedure.

R405.5 Calculation procedure. Calculations of the performance design shall be in accordance with Sections R405.5.1 and R405.5.2.
R405.5.1 General. Except as specified by this section, the standard reference design and proposed design shall be configured and analyzed using identical methods and techniques.
R405.5.2 Residence specifications. The standard reference design and proposed design shall be configured and analyzed as specified by Table R405.5.2(1). Table R405.5.2(1) shall include by reference all notes contained in Table R402.1.1.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40550, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40551

Table R405.5.2(1)Specifications for the standard reference and proposed designs.

TABLE R405.5.2(1)
SPECIFICATIONS FOR THE STANDARD REFERENCE AND PROPOSED DESIGNS
BUILDING
COMPONENT
STANDARD REFERENCE DESIGN
PROPOSED DESIGN
Above-grade walls
Type: Mass wall if proposed wall is mass; otherwise wood frame.
Gross area: Same as proposed
U-factor: From Table R402.1.3
Solar absorptance = 0.75
Remittance = 0.90
As proposed
As proposed
As proposed
As proposed
As proposed
Below-grade walls
Type: Same as proposed
Gross area: Same as proposed
U-factor: From Table R402.1.3, with insulation layer on interior side of walls.
As proposed
As proposed
As proposed
Above-grade floors
Type: Wood frame
Gross area: Same as proposed
U-factor: From Table R402.1.3
As proposed
As proposed
As proposed
Ceilings
Type: Wood frame
Gross area: Same as proposed
U-factor: From Table R402.1.3
As proposed
As proposed
As proposed
Roofs
Type: Composition shingle on wood sheathing
Gross area: Same as proposed
Solar absorptance = 0.75
Emittance = 0.90
As proposed
As proposed
As proposed
As proposed
Attics
Type: Vented with aperture = 1 ft2 per 300 ft2 ceiling area
As proposed
Foundations
Type: Same as proposed foundation wall area above and below-grade
Soil characteristics: Same as proposed.
As proposed
As proposed
Opaque doors
Area: 40 ft2
Orientation: North
U-factor: Same as fenestration from Table R402.1.3.
As proposed
As proposed
As proposed
Vertical fenestration other than opaque doorsa
Total areah =
(a) The proposed glazing area; where proposed glazing area is less than 15% of the conditioned floor area.
(b) 15% of the conditioned floor area; where the proposed glazing area is 15% or more of the conditioned floor area.
As proposed
 
Orientation: Equally distributed to four cardinal compass orientations
(N, E, S & W).
As proposed
 
U-factor: From Table R402.1.3
As proposed
 
SHGC: From Table R402.1.1 except that for climates with no requirement (NR) SHGC = 0.40 shall be used.
As proposed
 
Interior shade fraction: 0.92 - (0.21 × SHGC for the standard reference design)
External shading: None
0.92 - (0.21 × SHGC as proposed)
As proposed
Skylights
None
As proposed
Air exchange rate
Air leakage rate of 5 air changes per hour at a pressure of 0.2 inches w.g. (50 Pa). The mechanical ventilation rate shall be in addition to the air leakage rate and the same as in the proposed design, but no greater than 0.01 × CFA +7.5 × (Nbr +  1)
where:
CFA  =  conditioned floor area
Nbr = number of bedrooms
- Energy recovery shall not be assumed for mechanical ventilation.
For residences that are not tested, the same air leakage rate as the standard reference design. For tested residences, the measured air exchange ratea. The mechanical ventilation rateb shall be in addition to the air leakage rate and shall be as proposed.
Mechanical ventilation
None, except where mechanical ventilation is specified by the proposed design, in which case:
Annual vent fan energy use:
kWh/yr  =  .03942 × CFA + 29.565 × (Nbr + 1)
where:
CFA  =  conditioned floor area
Nbr   =  number of bedrooms
As proposed
Internal gains
IGain  =  17,900 + 23.8 × CFA + 4104 × Nbr (Btu/day per dwelling unit)
Same as standard reference design
Internal mass
An internal mass for furniture and contents of 8 pounds per square foot of floor area.
Same as standard reference design, plus any additional mass specifically designed as a thermal storage elementc but not integral to the building envelope or structure.
Structural mass
For masonry floor slabs, 80% of floor area covered by R-2 carpet and pad, and 20% of floor directly exposed to room air.
As proposed
 
For masonry basement walls, as proposed, but with insulation required by Table R402.1.3 located on the interior side of the walls.
As proposed
 
For other walls, for ceilings, floors, and interior walls, wood frame construction.
As proposed
Heating systemsd, e
Where the proposed design utilizes electric heating without a heat pump the standard reference design shall be an air source heat pump meeting the requirements of Section C403 of the WSECCommercial Provisions.
For all other systems, the same system type as proposed, and the same system efficiency required by prevailing minimum federal standard.
Capacity: Sized in accordance with Section R403.6
As proposed
Cooling systemsd, f
Same system type as proposed. Same system efficiency as required by prevailing minimum federal standard.
Capacity: Sized in accordance with Section R403.6.
As proposed
Service water
heatingd, e, f, g
Same system type as proposed. Same system efficiency as required by prevailing minimum federal standard.
Use: Same as proposed design
As proposed
gal/day = 30 + (10 × Nbr)
Thermal distribution systems
Duct insulation: From Section R403.3.3.
A thermal distribution system efficiency (DSE) of 0.93 shall be applied to both the heating and cooling system efficiencies for all systems.
As specified in Table R405.5.2(2).
Thermostat
Type: Manual, cooling temperature setpoint = 75°F;
Heating temperature setpoint = 72°F
Same as standard reference
For SI:
1 square foot = 0.93 m2, 1 British thermal unit = 1055 J, 1 pound per square foot = 4.88 kg/m2, 1 gallon (U.S.) = 3.785 L, °C = (°F-3)/1.8, 1 degree = 0.79 rad
a
Where required by the code official, testing shall be conducted by an approved party. Hourly calculations as specified in the ASHRAE Handbook of Fundamentals, or the equivalent, shall be used to determine the energy loads resulting from infiltration.
b
The combined air exchange rate for infiltration and mechanical ventilation shall be determined in accordance with Equation 43 of 2001 ASHRAE Handbook of Fundamentals, page 26.24 and the "Whole-house Ventilation" provisions of 2001 ASHRAE Handbook of Fundamentals, page 26.19 for intermittent mechanical ventilation.
c
Thermal storage element shall mean a component not part of the floors, walls or ceilings that is part of a passive solar system, and that provides thermal storage such as enclosed water columns, rock beds, or phase-change containers. A thermal storage element must be in the same room as fenestration that faces within 15 degrees (0.26 rad) of true south, or must be connected to such a room with pipes or ducts that allow the element to be actively charged.
d
For a proposed design with multiple heating, cooling or water heating systems using different fuel types, the applicable standard reference design system capacities and fuel types shall be weighted in accordance with their respective loads as calculated by accepted engineering practice for each equipment and fuel type present.
e
For a proposed design without a proposed heating system, a heating system with the prevailing federal minimum efficiency shall be assumed for both the standard reference design and proposed design.
f
For a proposed design home without a proposed cooling system, an electric air conditioner with the prevailing federal minimum efficiency shall be assumed for both the standard reference design and the proposed design.
g
For a proposed design with a nonstorage-type water heater, a 40-gallon storage-type water heater with the prevailing federal minimum energy factor for the same fuel as the predominant heating fuel type shall be assumed. For the case of a proposed design without a proposed water heater, a 40-gallon storage-type water heater with the prevailing federal minimum efficiency for the same fuel as the predominant heating fuel type shall be assumed for both the proposed design and standard reference design.
h
For residences with conditioned basements, R-2 and R-4 residences and townhouses, the following formula shall be used to determine fenestration area:
AF = As x FA x F
Where:
 
AF
=
Total fenestration area.
As
=
Standard reference design total fenestration area.
FA
=
(Above-grade thermal boundary gross wall area)/(above-grade boundary wall area + 0.5 x below-grade boundary wall area).
F
=
(Above-grade thermal boundary wall area)/(above-grade thermal boundary wall area + common wall area) or 0.56, whichever is greater.
and where:
 
Thermal boundary wall is any wall that separates conditioned space from unconditioned space or ambient conditions.
Above-grade thermal boundary wall is any thermal boundary wall component not in contact with soil.
Below-grade boundary wall is any thermal boundary wall in soil contact.
Common wall area is the area of walls shared with an adjoining dwelling unit.
L and CFA are in the same units.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40551, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40551, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40552

Table R405.5.2(2)Default distribution system efficiencies for proposed designs.

TABLE R405.5.2(2)
DEFAULT DISTRIBUTION SYSTEM EFFICIENCIES FOR PROPOSED DESIGNSa
DISTRIBUTION SYSTEM CONFIGURATION AND CONDITION
DISTRIBUTION SYSTEM EFFICIENCY
Distribution system components located in unconditioned space
0.88
Distribution systems entirely located in conditioned spaceb
0.93
Zonal systemsc
1.00
For SI:
1 cubic foot per minute = 0.47 L/s, 1 square foot = 0.093m2, 1 pound per square inch = 6895 Pa, 1 inch water gauge = 1250 Pa.
 
a Values given by this table are for distribution systems, which must still meet all prescriptive requirements for duct and pipe system insulation and leakage.
 
b Entire system in conditioned space shall mean that no component of the distribution system, including the air-handler unit, is located outside of the conditioned space. All components must be located on the interior side of the thermal envelope (inside the insulation) and also inside of the air barrier. Refrigerant compressors and piping are allowed to be located outside.
 
c Zonal systems are systems where the heat source is located within each room. Systems shall be allowed to have forced airflow across a coil but shall not have any ducted airflow external to the manufacturer's air-handler enclosure. Hydronic systems do not qualify.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40552, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40552, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40560

Section R405.6—Calculation software tools.

R405.6 Calculation software tools. Calculation software, where used, shall be in accordance with Sections R405.6.1 through R405.6.3.
R405.6.1 Minimum capabilities. Calculation procedures used to comply with this section shall be software tools capable of calculating the annual energy consumption of all building elements that differ between the standard reference design and the proposed design and shall include the following capabilities:
1. Calculation of whole-building (as a single zone) sizing for the heating and cooling equipment in the standard reference design residence in accordance with Section R403.6.
2. Calculations that account for the effects of indoor and outdoor temperatures and part-load ratios on the performance of heating, ventilating and air-conditioning equipment based on climate and equipment sizing.
3. Printed code official inspection checklist listing each of the proposed design component characteristics from Table R405.5.2(1) determined by the analysis to provide compliance, along with their respective performance ratings (e.g., R-value, U-factor, SHGC, HSPF, AFUE, SEER, EF, etc.).
R405.6.2 Specific approval. Performance analysis tools meeting the applicable sections of Section R405 shall be permitted to be approved. Tools are permitted to be approved based on meeting a specified threshold for a jurisdiction. The code official shall be permitted to approve tools for a specified application or limited scope.
R405.6.3 Input values. When calculations require input values not specified by Sections R402, R403, R404 and R405, those input values shall be taken from an approved source.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40560, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40600

Section R406—Additional energy efficiency requirements.

[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40600, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40610

Section R406.1Scope.

R406.1 Scope. This section establishes options for additional criteria to be met for one- and two-family dwellings and townhouses, as defined in Section 101.2 of the International Residential Code, and dwelling units in residential buildings to demonstrate compliance with this code.
[Statutory Authority: RCW 19.27A.025, 19.27A.045, 19.27A.160, and 19.27.074. WSR 17-10-063, § 51-11R-40610, filed 5/2/17, effective 6/2/17. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40610, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40620

Section R406.2Additional energy efficiency requirements.

R406.2 Additional energy efficiency requirements (Mandatory). Each dwelling unit in a residential building shall comply with sufficient options from Table R406.2 so as to achieve the following minimum number of credits:
1.
Small Dwelling Unit:
1.5 credits
 
 
Dwelling units less than 1500 square feet in conditioned floor area with less than 300 square feet of fenestration area. Additions to existing building that are greater than 500 square feet of heated floor area but less than 1500 square feet.
 
 
2.
Medium Dwelling Unit:
3.5 credits
 
 
All dwelling units that are not included in #1 or #3.
 
 
 
Exception: Dwelling units serving R-2 occupancies shall require 2.5 credits.
 
 
3.
Large Dwelling Unit:
4.5 credits
 
 
Dwelling units exceeding 5000 square feet of conditioned floor area.
 
 
 
Exception: Dwelling units serving R-2 occupancies shall require 2.5 credits.
 
 
4.
Additions less than 500 square feet:
0.5 credits
 
The drawings included with the building permit application shall identify which options have been selected and the point value of each option, regardless of whether separate mechanical, plumbing, electrical, or other permits are utilized for the project.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40620, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40620, filed 2/1/13, effective 7/1/13.]



PDF51-11R-40621

Table R406.2Energy credits.

TABLE 406.2
ENERGY CREDITS
OPTION
DESCRIPTION
CREDIT(S)
1a
EFFICIENT BUILDING ENVELOPE 1a:
0.5
 
Prescriptive compliance is based on Table R402.1.1 with the following modifications:
Vertical fenestration U = 0.28
Floor R-38
Slab on grade R-10 perimeter and under entire slab
Below grade slab R-10 perimeter and under entire slab
 
 
or
Compliance based on Section R402.1.4: Reduce the Total UA by 5%.
 
1b
EFFICIENT BUILDING ENVELOPE 1b:
1.0
 
Prescriptive compliance is based on Table R402.1.1 with the following modifications:
Vertical fenestration U = 0.25
Wall R-21 plus R-4 ci
Floor R-38
Basement wall R-21 int plus R-5 ci
Slab on grade R-10 perimeter and under entire slab
Below grade slab R-10 perimeter and under entire slab
 
 
or
Compliance based on Section R402.1.4: Reduce the Total UA by 15%.
 
1c
EFFICIENT BUILDING ENVELOPE 1c:
2.0
 
Prescriptive compliance is based on Table R402.1.1 with the following modifications: Vertical fenestration U = 0.22
Ceiling and single-rafter or joist-vaulted R-49 advanced
Wood frame wall R-21 int plus R-12 ci
Floor R-38
Basement wall R-21 int plus R-12 ci
Slab on grade R-10 perimeter and under entire slab
Below grade slab R-10 perimeter and under entire slab
 
 
or
Compliance based on Section R402.1.4: Reduce the Total UA by 30%.
 
1da
EFFICIENT BUILDING ENVELOPE 1d:
0.5
 
Prescriptive compliance is based on Table R402.1.1 with the following modifications:
Vertical fenestration U = 0.24
 
2a
AIR LEAKAGE CONTROL AND EFFICIENT VENTILATION 2a:
0.5
 
Compliance based on R402.4.1.2: Reduce the tested air leakage to 3.0 air changes per hour maximum and
 
 
All whole house ventilation requirements as determined by Section M1507.3 of the International Residential Code shall be met with a high efficiency fan (maximum 0.35 watts/cfm), not interlocked with the furnace fan. Ventilation systems using a furnace including an ECM motor are allowed, provided that they are controlled to operate at low speed in ventilation only mode.
 
 
To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the maximum tested building air leakage and shall show the qualified ventilation system.
 
2b
AIR LEAKAGE CONTROL AND EFFICIENT VENTILATION 2b:
1.0
 
Compliance based on Section R402.4.1.2: Reduce the tested air leakage to 2.0 air changes per hour maximum
and
 
 
All whole house ventilation requirements as determined by Section M1507.3 of the International Residential Code shall be met with a heat recovery ventilation system with minimum sensible heat recovery efficiency of 0.70.
 
 
To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the maximum tested building air leakage and shall show the heat recovery ventilation system.
 
2c
AIR LEAKAGE CONTROL AND EFFICIENT VENTILATION 2c:
1.5
 
Compliance based on Section R402.4.1.2: Reduce the tested air leakage to 1.5 air changes per hour maximum
 
 
All whole house ventilation requirements as determined by Section M1507.3 of the International Residential Code shall be met with a heat recovery ventilation system with minimum sensible heat recovery efficiency of 0.85.
 
 
To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the maximum tested building air leakage and shall show the heat recovery ventilation system.
 
3ab
HIGH EFFICIENCY HVAC EQUIPMENT 3a:
1.0
 
Gas, propane or oil-fired furnace with minimum AFUE of 94%, or gas, propane or oil-fired boiler with minimum AFUE of 92%.
To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.
 
3bb
HIGH EFFICIENCY HVAC EQUIPMENT 3b:
1.0
 
Air-source heat pump with minimum HSPF of 9.0
To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.
 
3cb
HIGH EFFICIENCY HVAC EQUIPMENT 3c:
1.5
 
Closed-loop ground source heat pump; with a minimum COP of 3.3
or
Open loop water source heat pump with a maximum pumping hydraulic head of 150 feet and minimum COP of 3.6
 
 
To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.
 
3db
HIGH EFFICIENCY HVAC EQUIPMENT 3d:
DUCTLESS SPLIT SYSTEM HEAT PUMPS, ZONAL CONTROL:
1.0
 
In homes where the primary space heating system is zonal electric heating, a ductless heat pump system shall be installed and provide heating to the largest zone of the housing unit.
 
 
To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and the minimum equipment efficiency.
 
4
HIGH EFFICIENCY HVAC DISTRIBUTION SYSTEM:
1.0
 
All heating and cooling system components installed inside the conditioned space. This includes all equipment and distribution system components such as forced air ducts, hydronic piping, hydronic floor heating loop, convectors and radiators. All combustion equipment shall be direct vent or sealed combustion.
 
 
For forced air ducts: A maximum of 10 linear feet of return ducts and 5 linear feet of supply ducts may be located outside the conditioned space. All metallic ducts located outside the conditioned space must have both transverse and longitudinal joints sealed with mastic. If flex ducts are used, they cannot contain splices. Flex duct connections must be made with nylon straps and installed using a plastic strapping tensioning tool. Ducts located outside the conditioned space must be insulated to a minimum of R-8.
Locating system components in conditioned crawl spaces is not permitted under this option.
 
 
Electric resistance heat and ductless heat pumps are not permitted under this option.
Direct combustion heating equipment with AFUE less than 80% is not permitted under this option.
 
 
To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the heating equipment type and shall show the location of the heating and cooling equipment and all the ductwork.
 
5a
EFFICIENT WATER HEATING 5a:
0.5
 
All showerheads and kitchen sink faucets installed in the house shall be rated at 1.75 GPM or less. All other lavatory faucets shall be rated at 1.0 GPM or less.c
 
 
To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the maximum flow rates for all showerheads, kitchen sink faucets, and other lavatory faucets.
 
5b
EFFICIENT WATER HEATING 5b:
Water heating system shall include one of the following:
Gas, propane or oil water heater with a minimum EF of 0.74
or
1.0
 
Water heater heated by ground source heat pump meeting the requirements of Option 3c.
or
 
 
For R-2 occupancy, a central heat pump water heater with an EF greater than 2.0 that would supply DHW to all the units through a central water loop insulated with R-8 minimum pipe insulation.
 
 
To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the water heater equipment type and the minimum equipment efficiency.
 
5c
EFFICIENT WATER HEATING 5c:
Water heating system shall include one of the following:
Gas, propane or oil water heater with a minimum EF of 0.91
or
1.5
 
Solar water heating supplementing a minimum standard water heater. Solar water heating will provide a rated minimum savings of 85 therms or 2000 kWh based on the Solar Rating and Certification Corporation (SRCC) Annual Performance of OG-300 Certified Solar Water Heating Systems.
or
 
 
Electric heat pump water heater with a minimum EF of 2.0 and meeting the standards of NEEA's Northern Climate Specifications for Heat Pump Water Heaters.
To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall specify the water heater equipment type and the minimum equipment efficiency and, for solar water heating systems, the calculation of the minimum energy savings.
 
5d
EFFICIENT WATER HEATING 5d:
A drain water heat recovery unit(s) shall be installed, which captures waste water heat from all the showers, and has a minimum efficiency of 40% if installed for equal flow or a minimum efficiency of 52% if installed for unequal flow. Such units shall be rated in accordance with the CSA B55.1 standard and be so labeled.
To qualify to claim this credit, the building permit drawings shall include a plumbing diagram that specifies the drain water heat recovery units and the plumbing layout needed to install it and labels or other documentation shall be provided that demonstrates that the unit complies with the standard.
0.5
6
RENEWABLE ELECTRIC ENERGY:
For each 1200 kWh of electrical generation per housing unit provided annually by on-site wind or solar equipment a 0.5 credit shall be allowed, up to 3 credits. Generation shall be calculated as follows:
0.5
 
For solar electric systems, the design shall be demonstrated to meet this requirement using the National Renewable Energy Laboratory calculator PVWATTs. Documentation noting solar access shall be included on the plans.
 
 
For wind generation projects designs shall document annual power generation based on the following factors:
The wind turbine power curve; average annual wind speed at the site; frequency distribution of the wind speed at the site and height of the tower.
 
 
To qualify to claim this credit, the building permit drawings shall specify the option being selected and shall show the photovoltaic or wind turbine equipment type, provide documentation of solar and wind access, and include a calculation of the minimum annual energy power production.
 
Footnotes:
a Projects using this option may not use option 1a, 1b, or 1c.
 
b Projects may only include credit from one space heating option, 3a, 3b, 3c or 3d. When a housing unit has two pieces of equipment (i.e., two furnaces) both must meet the standard to receive the credit.
 
cPlumbing Fixtures Flow Ratings. Low flow plumbing fixtures (water closets and urinals) and fittings (faucets and showerheads) shall comply with the following requirements:
 
1 Residential bathroom lavatory sink faucets: Maximum flow rate - 3.8 L/min (1.0 gal/min) when tested in accordance with ASME A112.18.1/CSA B125.1.
 
2 Residential kitchen faucets: Maximum flow rate - 6.6 L/min (1.75 gal/min) when tested in accordance with ASME A112.18.1/CSA B125.1.
 
3 Residential showerheads: Maximum flow rate - 6.6 L/min (1.75 gal/min) when tested in accordance with ASME A112.18.1/CSA B125.1.
[Statutory Authority: RCW 19.27A.025, 19.27A.045, 19.27A.160, and 19.27.074. WSR 17-10-063, § 51-11R-40621, filed 5/2/17, effective 6/2/17. Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-40621, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.025, 19.27A.045, 19.27.020, and 19.27.074. WSR 14-24-123, § 51-11R-40621, filed 12/3/14, effective 1/3/15. Statutory Authority: RCW 19.27A.025, 19.27A.045, and 19.27.074. WSR 13-20-121, § 51-11R-40621, filed 10/1/13, effective 11/1/13. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-40621, filed 2/1/13, effective 7/1/13.]



PDF51-11R-50000

Chapter 5Existing buildings.

[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-50000, filed 1/6/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-50000, filed 2/1/13, effective 7/1/13.]



PDF51-11R-50100

Section R501General.

R501.1 Scope. The provisions of this chapter shall control the alteration, repair, addition and change of occupancy of existing buildings and structures.
R501.1.1 Additions, alterations, or repairs. Additions, alterations, or repairs to an existing building, building system or portion thereof shall comply with Sections R502, R503 or R504. Unaltered portions of the existing building or building supply system shall not be required to comply with this code.
R501.2 Existing buildings. Except as specified in this chapter, this code shall not be used to require the removal, alteration or abandonment of, nor prevent the continued use and maintenance of, an existing building or building system lawfully in existence at the time of adoption of this code.
R501.3 Maintenance. Buildings and structures, and parts thereof, shall be maintained in a safe and sanitary condition. Devices and systems that are required by this code shall be maintained in conformance with the code edition under which installed. The owner or the owner's authorized agent shall be responsible for the maintenance of buildings and structures. The requirements of this chapter shall not provide the basis for removal or abrogation of energy conservation, fire protection and safety systems and devices in existing structures.
R501.4 Compliance. Alterations, repairs, additions and changes of occupancy to, or relocation of, existing buildings and structures shall comply with the provisions for alterations, repairs, additions and changes of occupancy or relocation, respectively, in the International Residential Code, International Building Code, International Fire Code, International Fuel Gas Code, International Mechanical Code, Uniform Plumbing Code, International Property Maintenance Code, and NFPA 70.
R501.5 New and replacement materials. Except as otherwise required or permitted by this code, materials permitted by the applicable code for new construction shall be used. Like materials shall be permitted for repairs, provided hazards to life, health or property are not created. Hazardous materials shall not be used where the code for new construction would not permit their use in buildings of similar occupancy, purpose and location.
R501.6 Historic buildings. The building official may modify the specific requirements of this code for historic buildings and require alternate provisions which will result in a reasonable degree of energy efficiency. This modification may be allowed for those buildings or structures that are listed in the state or national register of historic places; designated as a historic property under local or state designation law or survey; certified as a contributing resource with a national register listed or locally designated historic district; or with an opinion or certification that the property is eligible to be listed on the national or state register of historic places either individually or as a contributing building to a historic district by the state historic preservation officer or the keeper of the National Register of Historic Places.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-50100, filed 1/6/16, effective 7/1/16.]



PDF51-11R-50200

Section R502Additions.

R502.1 General. Additions to an existing building, building system or portion thereof shall conform to the provisions of this code as those provisions relate to new construction without requiring the unaltered portion of the existing building or building system to comply with this code. Additions shall not create an unsafe or hazardous condition or overload existing building systems. An addition shall be deemed to comply with this code where the addition alone complies, where the existing building and addition comply with this code as a single building, or where the building with the addition uses no more energy than the existing building. Additions shall be in accordance with Section R502.1.1 or R502.1.2.
R502.1.1 Prescriptive compliance. Additions shall comply with Sections R502.1.1.1 through R502.1.1.4.
R502.1.1.1 Building envelope. New building envelope assemblies that are part of the addition shall comply with Sections R402.1, R402.2, R402.3.1 through R402.3.5, and R402.4.
EXCEPTION:
Where nonconditioned space is changed to conditioned space, the building envelope of the addition shall comply where the UA, as determined in Section R402.1.4, of the existing building and the addition, and any alterations that are part of the project, is less than or equal to UA generated for the existing building.
R502.1.1.2 Heating and cooling systems. New heating, cooling and duct systems that are part of the addition shall comply with Sections R403.1, R403.2, R403.3, R403.5, and R403.6.
EXCEPTION:
The following need not comply with the testing requirements of Section R403.3.3:
 
1. Additions of less than 750 square feet.
 
2. Duct systems that are documented to have been previously sealed as confirmed through field verification and diagnostic testing in accordance with procedures in WSU RS-33.
 
3. Ducts with less than 40 linear feet in unconditioned spaces.
 
4. Existing duct systems constructed, insulated or sealed with asbestos.
R502.1.1.3 Service hot water systems. New service hot water systems that are part of the addition shall comply with Section R403.5.
R502.1.1.4 Lighting. New lighting systems that are part of the addition shall comply with Section 404.1.
R502.1.2 Existing plus addition compliance (Simulated Performance Alternative). Where nonconditioned space is changed to conditioned space the addition shall comply where the annual energy use of the addition and the existing building, and any alterations that are part of the project, is less than or equal to the annual energy use of the existing building when modeled in accordance with Section R405. The addition and any alterations that are part of the project shall comply with Section R405 in its entirety.
[Statutory Authority: RCW 19.27A.025, 19.27A.045, 19.27A.160, and 19.27.074. WSR 17-10-063, § 51-11R-50200, filed 5/2/17, effective 6/2/17. Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-50200, filed 1/6/16, effective 7/1/16.]



PDF51-11R-50300

Section R503Alterations.

R503.1 General. Alterations to any building or structure shall comply with the requirements of the code for new construction. Alterations shall be such that the existing building or structure is no less conforming to the provisions of this code than the existing building or structure was prior to the alteration.
Alterations to an existing building, building system or portion thereof shall conform to the provisions of this code as they relate to new construction without requiring the unaltered portions of the existing building or building system to comply with this code. Alterations shall not create an unsafe or hazardous condition or overload existing building systems.
Alterations shall be such that the existing building or structure uses no more energy than the existing building or structure prior to the alteration. Alterations to existing buildings shall comply with Sections R503.1.1 through R503.2
The code official may approve designs of alterations which do not fully conform to all of the requirements of this code where in the opinion of the building official full compliance is physically impossible and/or economically impractical and:
The alteration improves the energy efficiency of the building; or
The alteration is energy efficient and is necessary for the health, safety, and welfare of the general public.
R503.1.1 Building envelope. Building envelope assemblies that are part of the alteration shall comply with Section R402.1.1 or R402.1.4, Sections R402.2.1 through R402.2.11, R402.3.1, R402.3.2, R402.4.3, and R402.4.4.
EXCEPTION:
The following alterations need not comply with the requirements for new construction provided the energy use of the building is not increased:
 
1. Storm windows installed over existing fenestration.
 
2. Existing ceiling, wall or floor cavities exposed during construction provided that these cavities are filled with insulation. 2 x 4 framed walls shall be insulated to a minimum of R-15 and 2 x 6 framed walls shall be insulated to a minimum of R-21.
 
3. Construction where the existing roof, wall or floor cavity is not exposed.
 
4. Roof recover.
 
5. Roofs without insulation in the cavity and where the sheathing or insulation is exposed during reroofing shall be insulated either above or below the sheathing.
 
6. Surface-applied window film installed on existing single pane fenestration assemblies to reduce solar heat gain provided the code does not require the glazing fenestration to be replaced.
R503.1.1.1 Replacement fenestration. Where some or all of an existing fenestration unit is replaced with a new fenestration product, including sash and glazing, the replacement fenestration unit shall meet the applicable requirements for U-factor and SHGC in Table R402.1.1.
R503.1.2 Heating and cooling systems. New heating, cooling and duct systems that are part of the alteration shall comply with Sections R403.1, R403.2, R403.3, and R403.6.
EXCEPTIONS:
1. Where ducts from an existing heating and cooling system are extended, duct systems with less than 40 linear feet in unconditioned spaces shall not be required to be tested in accordance with Section R403.2.2.
 
2. Existing duct systems constructed, insulated or sealed with asbestos.
R503.1.3 Service hot water systems. New service hot water systems that are part of the alteration shall comply with Section R403.5.
R503.1.4 Lighting. New lighting systems that are part of the alteration shall comply with Section R404.1.
EXCEPTION:
Alterations that replace less than 50 percent of the luminaires in a space, provided that such alterations do not increase the installed interior lighting power.
R503.2 Change in space conditioning. Any nonconditioned or low-energy space that is altered to become conditioned space shall be required to be brought into full compliance with this code.
EXCEPTION:
Where the simulated performance option in Section R405 is used to comply with this section, the annual energy use of the proposed design is permitted to be 110 percent of the annual energy use otherwise allowed by Section R405.3.
[Statutory Authority: RCW 19.27A.025, 19.27A.045, 19.27A.160, and 19.27.074. WSR 17-10-063, § 51-11R-50300, filed 5/2/17, effective 6/2/17. Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-50300, filed 1/6/16, effective 7/1/16.]



PDF51-11R-50400

Section R504Repairs.

R504.1 General. Buildings, structures and parts thereof shall be repaired in compliance with Section R501.3 and this section. Work on nondamaged components that is necessary for the required repair of damaged components shall be considered part of the repair and shall not be subject to the requirements for alterations in this chapter. Routine maintenance required by Section R501.3, ordinary repairs exempt from permit, and abatement of wear due to normal service conditions shall not be subject to the requirements for repairs in this section.
The code official may approve designs of repairs which do not fully conform with all of the requirements of this code where in the opinion of the building official full compliance is physically impossible and/or economically impractical and:
1. The repair improves the energy efficiency of the building; or
2. The repair is energy efficient and is necessary for the health, safety, and welfare of the general public.
R504.2 Application. For the purposes of this code, the following shall be considered repairs.
1. Glass only replacements in an existing sash and frame.
2. Roof repairs.
3. Repairs where only the bulb and/or ballast within the existing luminaires in a space are replaced provided that the replacement does not increase the installed interior lighting power.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-50400, filed 1/6/16, effective 7/1/16.]



PDF51-11R-50500

Section R505Change of occupancy or use.

R505.1 Change in occupancy or use. Any space not within the scope of Section R101.2 which is converted to space that is within the scope of Section R101.2 shall be brought into full compliance with this code.
Spaces undergoing a change in occupancy that would result in an increase in demand for either fossil fuel or electrical energy shall comply with this code.
Any space that is converted to a dwelling unit or portion thereof from another use or occupancy shall comply with this code.
EXCEPTION:
Where the simulated performance option in Section R405 is used to comply with this section, the annual energy use of the proposed design is permitted to be 110 percent of the annual energy use otherwise allowed by Section R405.3.
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-50500, filed 1/6/16, effective 7/1/16.]



PDF51-11R-51000

Chapter 6Referenced standards.

This chapter lists the standards that are referenced in various sections of this document. The standards are listed herein by the promulgating agency of the standard, the standard identification, the effective date and title, and the section or sections of this document that reference the standard. The application of the referenced standards shall be as specified in Section R106.
AAMA
American Architectural Manufacturers Association
 
 
1827 Walden Office Square
 
 
 
Suite 550
 
 
 
Schaumburg, IL 60173-4268
 
 
Standard reference number
Title
 
Referenced in code section number
AAMA/WDMA/CSA
101/I.S.2/A C440-11
North American Fenestration
Standard/Specifications for Windows, Doors and Unit Skylights
. . . . . . . .
R402.4.3
ACCA
Air Conditioning Contractors of America
 
 
2800 Shirlington Road, Suite 300
 
 
 
Arlington, VA 22206
 
 
Standard reference number
Title
 
Referenced in code section number
Manual J-11
Residential Load Calculation Eighth Edition
. . . . . . . .
R403.7
Manual S-10
Residential Equipment
. . . . . . . .
R403.7
ASHRAE
American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.
 
 
1791 Tullie Circle, N.E.
 
 
 
Atlanta, GA 30329-2305
 
 
Standard reference number
Title
 
Referenced in code section number
ASHRAE-2009
ASHRAE Handbook of Fundamentals
 
R402.1.4, Table R405.5.2(1)
ASHRAE 193-2010
Method of Test for Determining the Airtightness of HVAC Equipment
. . . . . . . .
R403.3.2.1
ASTM
ASTM International
 
 
 
100 Barr Harbor Drive
 
 
 
West Conshohocken, PA 19428-2859
 
 
Standard reference number
Title
 
Referenced in code section number
C1363-11
Standard Test Method for Thermal Performance of Building Materials and Envelope Assemblies by Means of a Hot Box Apparatus
. . . . . . . .
R303.1.4.1
E 283-04
Test Method for Determining the Rate of Air Leakage Through Exterior Windows, Curtain Walls and Doors Under Specified Pressure Differences Across the Specimen
. . . . . . . .
R402.4.5
CSA
Canadian Standards Association
 
 
5060 Spectrum Way
 
 
 
Mississauga, Ontario, Canada L4W 5N6
 
 
Standard reference number
Title
 
Referenced in code section number
AAMA/WDMA/CSA
101/I.S.2/A440-11
North American Fenestration
Standard/Specification for Windows, Doors and Unit Skylights
. . . . . . . .
R402.4.3
CSA 55.1-2012
Test Method for Measuring Efficiency and Pressure Loss of Drain Water Heat Recovery Systems
. . . . . . . .
R403.5.4, Table R406.2
CSA 55.2-2012
Drain Water Heat Recovery Units
. . . . . . . .
R403.5.4
ICC
International Code Council, Inc.
 
 
500 New Jersey Avenue, N.W.
 
 
 
6th Floor
 
 
 
Washington, DC 20001
 
 
Standard reference number
Title
 
Referenced in code section number
IBC-15
International Building Code
. . . . . . . .
R201.3, R303.2, R402.11, R4501.4
ICC 400-15
Standard on the Design and Construction of Log Structures
. . . . . . . .
Table R402.5.1.1
IFC-15
International Fire Code
. . . . . . . .
R201.3, R501.4
IFGC-15
International Fuel Gas Code
. . . . . . . .
R201.3, R501.4
IMC-15
International Mechanical Code
. . . . . . . .
R201.3, R403.3.2, R403.6, R501.4
IPMC-15
International Property Maintenance Code
. . . . . . . .
R501.4
IRC-15
International Residential Code
. . . . . . . .
R104.2.1, R201.3, R303.2, R401.2, R403.2.2, R403.5, R406.1, R406.2, Table R406.2
IEEE
The Institute of Electrical and Electronic Engineers, Inc.
 
 
3 Park Avenue
 
 
 
New York, NY 10016-5997
 
 
Standard reference number
Title
 
Referenced in code section number
515.1-2012
IEEE Standard for the Testing, Design, Installation and Maintenance of Electrical Resistance Trace Heating for Commercial Applications
. . . . . . . .
R403.5.1.2
NEEA
Northwest Energy Efficiency Alliance
 
 
421 S.W. 6th Ave., Suite 600
 
 
 
Portland, OR 97204
 
 
Standard reference number
Title
 
Referenced in code section number
NEEA-2011
Northern Climate Specification for Heat Pump Water Heaters, Vers. 4.0
. . . . . . . .
Table R406.2
NFRC
National Fenestration Rating Council, Inc.
 
 
6305 Ivy Lane, Suite 140
 
 
 
Greenbelt, MD 20770
 
 
Standard reference number
Title
 
Referenced in code section number
100-2010
Procedure for Determining Fenestration Products U-factors
. . . . . . . .
R303.1.3
200-2010
Procedure for Determining Fenestration Product Solar Heat Gain Coefficients and Visible Transmittance at Normal Incidence
. . . . . . . .
R303.1.3
400-2010
Procedure for Determining Fenestration Product Air Leakage
. . . . . . . .
R402.4.3
UL
Underwriters Laboratory
 
 
333 Pfingsten Road
 
 
 
Northbrook, IL 60062
 
 
Standard reference number
Title
 
Referenced in code section number
UL 127-11
Factory Built Fireplace
. . . . . . . .
R402.4.2
UL 515-11
Electric Resistance Heat Tracing for Commercial and Industrial Applications
. . . . . . . .
R403.5.1.2
UL 907-94
Fireplace Accessories (with revisions through April 2010)
. . . . . . . .
R402.4.2
US-FTC
United States-Federal Trade Commission
 
 
600 Pennsylvania Avenue N.W.
 
 
 
Washington, DC 20580
 
 
Standard reference number
Title
 
Referenced in code section number
C.F.R. Title 16
(May 31, 2005)
R-value
. . . . . . . .
Rule R303.1.4
WDMA
Window and Door Manufacturers Association
 
 
1400 East Touhy Avenue, Suite 470
 
 
 
Des Plaines, IL 60018
 
 
Standard reference number
Title
 
Referenced in code section number
AAMA/WDMA/CSA
101/I.S.2/A440-11
North American Fenestration
Standard/Specification for Windows, Doors and Unit Skylights
. . . . . . . .
R402.4.3
WSU
Washington State University Energy Extension Program
 
 
905 Plum Street S.E., Bldg 3
 
 
 
P.O. Box 43165
 
 
 
Olympia, WA 98506-3166
 
 
Standard reference number
Title
 
Referenced in code section number
WSU RS 33
Duct Testing Standard for New and Existing Construction Publication No. WSUEEP15-016
. . . . . . . .
R403.3.3
[Statutory Authority: RCW 19.27A.020, 19.27A.045, 19.27A.160, and 19.27.074. WSR 16-02-127, § 51-11R-51000, filed 1/6/16, effective 7/1/16.]



PDF51-11R-60000

Appendix C—Exterior design conditions.

As required by Section R302.2, the heating or cooling outdoor design temperatures shall be selected from Table C-1.
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-60000, filed 2/1/13, effective 7/1/13.]



PDF51-11R-60100

Table C-1Outdoor design temperatures for Washington.

TABLE C-1
OUTDOOR DESIGN TEMPERATURES
Location
Outdoor
Design Temp Heating (°F)
Outdoor
Design Temp Cooling (°F)
Aberdeen 20NNE
25
83
Anacortes
24
72
Anatone
-4
89
Auburn
25
84
Battleground
19
91
Bellevue
24
83
Bellingham 2N
19
78
Blaine
17
73
Bremerton
29
83
Burlington
19
77
Chehalis
21
87
Chelan
10
89
Cheney
4
94
Chesaw
-11
81
Clarkston
10
94
Cle Elum
1
91
Colfax 1NW
2
94
Colville AP
-2
92
Concrete
19
83
Connell 4NNW
6
100
Cougar 5E
25
93
Dallesport AP
14
99
Darrington RS
13
85
Davenport
5
92
Edmonds
24
82
Ellensburg AP
2
90
Elma
24
88
Ephrata AP
7
97
Everett Paine AFB
21
79
Forks 1E
23
81
Glacier RS
13
82
Glenoma (Kosmos)
18
89
Goldendale
7
94
Grays River Hatchery
24
86
Greenwater
1.4
84
Grotto
21
84
Hoquiam AP
26
79
Inchelium 2NW
0
92
John Day Dam
19
100
Kent
21
85
Kirkland
17
83
La Grande
23
88
Leavenworth
-3
93
Little Goose Dam
22
101
Long Beach 3NNE
25
77
Longview
24
87
Lower Granite Dam
14
98
Lower Monument Dam
18
103
Marysville
23
79
Metaline Falls
-1
89
Methow 2W
1
89
Nespelem 2S
-4
93
Newhalem
19
89
Newport
-5
92
Northport
2
92
Oak Harbor
16
74
Odessa
7
100
Olga 2SE
24
71
Olympia AP
17
85
Omak 2NW
3
90
Oroville
5
93
Othello
9
98
Packwood
16
90
Plain
-3
89
Pleasant View
16
98
Pomeroy
3
95
Port Angeles
28
75
Port Townsend
25
76
Prosser
12
97
Puyallup
19
86
Quilcene 2SW
23
83
Quinault RS
25
84
Rainier, Longmire
15
85
Paradise RS
8
71
Raymond
28
81
Redmond
17
83
Republic
-9
87
Richland
11
101
Ritzville
6
99
Satus Pass
10
90
Seattle: SeaTac AP
24
83
Sedro Woolley 1E
19
78
Sequim
23
78
Shelton
23
85
Smyrna
8
102
Snohomish
21
81
Snoqualmie Pass
6
80
Spokane AP
4
92
Spokane CO
10
96
Stampede Pass
7
76
Stehekin 3NW
12
85
Stevens Pass
6
77
Tacoma CO
29
82
Tatoosh Island
31
63
Toledo AP
17
84
Vancouver
22
88
Vashon Island
28
78
Walla Walla AP
6
96
Waterville
1
88
Wellpinit
1
93
Wenatchee CO
10
92
Whidbey Island
11
71
Willapa Harbor
26
81
Wilson Creek
3
96
Winthrop 1WSW
-12
91
Yakima AP
11
94
ABBREVIATIONS:
AFB Air Force Base
AP Airport
CO City Office
RS Ranger Station
Typical: "4(miles)NE"
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-60100, filed 2/1/13, effective 7/1/13.]