Washington Revised Code Title 59. Landlord and Tenant § 59.20.045. Enforceability of rules against a tenant

(1) Their purpose is to promote the convenience, health, safety, or welfare of the residents, protect and preserve the premises from abusive use, or make a fair distribution of services and facilities made available for the tenants generally;

(2) They are reasonably related to the purpose for which they are adopted;

(3) They apply to all tenants in a fair manner;

(4) They are not for the purpose of evading an obligation of the landlord;

(5) They are not retaliatory or discriminatory in nature; and

(6) With respect to any new or amended rules not contained within the rental agreement, the tenant was provided at least thirty days' written notice of the new or amended rule. The tenant must be provided with at least three months to comply with the new or amended rule after the thirty-day notice period. Within the three-month grace period, any violation of the new or amended rule must result in a warning only. After expiration of the three-month grace period, any violation of the new or amended rule subjects the tenant to termination of the tenancy as authorized under RCW 59.20.080(1)(a).