Summer 2023

Governor Inslee signed E2SHB 1110 in May 2023 and the law took effect July 23, 2023. The bill rewrites residential zoning rules across most of urban Washington, requiring cities to allow duplexes, triplexes, fourplexes, cottage housing, courtyard apartments, and stacked flats in areas that were previously zoned single-family only.

The bill sets three city tiers. Tier A cities (population 75,000 and above) must permit at least four homes per residential lot — six per lot within a quarter-mile of major transit or if two of the homes are income-restricted affordable. Tier B cities (25,000-75,000) must allow at least two homes per lot, four near transit. Tier C cities under 25,000 that sit inside a contiguous urban growth area must allow at least two homes per lot. Compliance is tied to each city's next comprehensive plan update; King, Snohomish, and Pierce County jurisdictions finalized their updates in December 2024, with most new zoning ordinances expected by mid-2025.

For brokers, the practical impact is large and lasting: more than 1.2 million existing homes across the state now sit on parcels zoned for two to six units plus accessory dwellings. Listing-side valuation conversations need to account for redevelopment potential, not just the existing structure. Buyer-side, lot suitability questions (utility hookups, setbacks, tree retention) become a routine part of due diligence on what used to be a routine single-family purchase. The bill summary on leg.wa.gov and the final House Bill Report have the statutory text and tier definitions.