RCW 35.21.830

The imposition of controls on rent is of statewide significance and is preempted by the state. No city or town of any class may enact, maintain, or enforce ordinances or other provisions which regulate the amount of rent to be charged for single-family or multiple-unit residential rental structures or sites other than properties in public ownership, under public management, or properties providing low-income rental housing under joint public-private agreements for the financing or provision of such low-income rental housing. This section shall not be construed as prohibiting any city or town from entering into agreements with private persons which regulate or control the amount of rent to be charged for rental properties.