Wash. Admin. Code § 162-38-080
(2) Unfair to unreasonably prohibit modifications needed by disabled tenant. Whether or not the landlord permits tenants in general to make alterations or additions to a structure, it is an unfair practice under RCW 49.60.222 for a landlord to refuse to allow a disabled tenant to make reasonable alterations or additions to the structure or fixtures under the following conditions:
(3) Examples of appropriate modifications. The following are examples of alterations or additions commonly needed to make real property accessible to disabled persons:
[Statutory Authority: RCW 49.60.120(3) and 49.60.240. WSR 96-13-045, § 162-38-080, filed 6/13/96, effective 7/14/96. Statutory Authority: RCW 49.60.120(3). WSR 82-19-086 (Order 41), § 162-38-080, filed 9/22/82.]