This bill adds new sections to several chapters of the Revised Code of Washington so that cities and counties planning under RCW 36.70A.040 must allow up to two mobile dwellings on each lot zoned for residential use when the lot already has at least one housing unit, is inside an urban growth area, and the mobile dwelling is not located in state shorelines or in designated natural resource lands and critical areas. It defines "mobile dwelling" to include towable or vehicular recreational units and tiny houses on wheels. The bill sets technical requirements for utility hookups: dedicated electrical outlets with at least a 20‑amp, GFCI‑protected circuit; plumbing and sewer hookup rules for units with internal plumbing; and provision of potable water, toilets, and showers in an existing unit when internal plumbing is absent. Cities must use standard permitting and inspection procedures for new utility hookups and may not require inspection of the mobile dwelling itself. Legally, the measure creates new law by adding sections to chapter 36.70A RCW and to chapters governing apartment owner, condominium, and homeowners’ associations and common interest communities (chapters 64.32, 64.34, 64.38, and 64.90 RCW). It is a procedural and substantive zoning/planning change (requiring allowance of mobile dwellings and setting hookup standards) and a preemption of certain private association restrictions that would otherwise prohibit the required mobile dwellings. Sections added to chapters 64.32, 64.34, and 64.38 RCW expire January 1, 2028. The act also conditions its validity on specific funding being provided and referenced in the omnibus appropriations act by June 30, 2025; if that funding is not provided, the act is null and void. The text provided does not specify the act’s effective date, does not state the funding amount or source required for enactment, does not identify which counties qualify under RCW 36.70A.040, and does not describe enforcement mechanisms, penalties, or procedures for noncompliance. It also does not state whether the new section added to chapter 64.90 RCW has an expiration date.

If enacted, homeowners in cities and counties that plan under state growth laws would generally be allowed to place up to two mobile dwellings on a residential lot that already has a house and is inside an urban growth area, so long as the units are not on shorelines or in designated natural resource or critical areas. That would give property owners a clearer option to add small, wheeled living units and require local permitting offices to handle only standard electrical and utility hookups (including a 20‑amp GFCI circuit, potable water hookups with backflow prevention, and sewer lateral connections), while associations for condos, apartments, and homeowner common interest communities would be barred from enforcing rules that effectively prohibit those units for a limited period. Cities, counties, water systems, utility providers, and homeowners would see the most direct changes: local governments must update plans or ordinances on the stated schedule and process routine utility permits, water systems must inspect backflow assemblies as required, homeowners face hookup and minor construction costs, and associations lose some control over covenants until the stated expirations. The bill’s practical effect depends on an unspecified effective date and on whether specific funding is approved by June 30, 2025 (the act is void without that funding), and the text doesn’t make clear which counties are covered or how noncompliance would be enforced.