(1) A petition for review may be amended as a matter of right until fourteen days after its date of filing. Any such amendments shall be limited to amending the legal bases for challenging the matters raised in the original petition, but may not raise new challenges to the ordinance.

(2) Thereafter any amendments shall be requested in writing by motion, and will be made only after approval by the presiding officer. Amendments shall not be freely granted and may be denied upon a showing by the adverse party of unreasonable and unavoidable hardship, or by the presiding officer's finding that granting the same would adversely impact the board's ability to meet the time requirements of RCW 36.70A.300 for issuing a final order.

(3) At the prehearing conference the presiding officer will work with the parties to clarify the issues raised in the petition for review. The presiding officer may, upon motion of a party or upon its own motion, require a more complete or concise statement of the issues presented for resolution by the board.