Legislation to Lift Local Prohibition of Middle Housing Proposed in Washington State

Washington State is the latest example of a state that wants to preempt local planning law to make it easier to add housing units to single-family residential properties all over the states.

1 minute read

January 23, 2020, 9:00 AM PST

By James Brasuell @CasualBrasuell


Missing Middle Housing

A SE Portland duplex. | Sightline Institute: Missing Middle Homes Photo Library / Flickr

Dan Bertolet reports on statewide legislation introduced yesterday in Washington by State Representative Nicole Macri (D-Seattle) that would "lift local bans on small-scale, multiple-dwelling homes known as 'middle housing,'"

As explained by Bertolet, HB 2780 would re-legalize, "triplexes on any lot, and up to sixplexes in single-detached house zones in counties and cities of 15,000 or more," as well as, "duplexes on any lot in all cities between 10,000 and 15,000."

HB 2780 joins a growing roster of bills currently under consideration in the Washington Legislature that would ease zoning restrictions and other forms of housing regulation around the state. HB 2570 would ease the construction of backyard cottages and mother-in-law apartments. HB 1923, approved in 2019, increased building capacity around the state, but through incentives rather than a mandate.

HB2780 also joins a growing roster of bills in other states that would preempt local law to allow for more density in single-family zones around the state. Oregon already passed a law, but California, Maryland, Virginia, and Nebraska are considering similar reforms of the traditional single-family zoning designation to allow more space for homes of different sizes in residential neighborhoods.

Tuesday, January 21, 2020 in Sightline Institute

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Get top-rated, practical training

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

April 30, 2025 - Diana Ionescu

Close-up on Canadian flag with Canada Parliament building blurred in background.

Canada vs. Kamala: Whose Liberal Housing Platform Comes Out on Top?

As Canada votes for a new Prime Minister, what can America learn from the leading liberal candidate of its neighbor to the north?

April 28, 2025 - Benjamin Schneider

Hot air balloons rise over Downtown Boise with the State Capitol building visible amidst the high rises.

The Five Most-Changed American Cities

A ranking of population change, home values, and jobs highlights the nation’s most dynamic and most stagnant regions.

April 23, 2025 - GoodMigrations

Sleeping in Public

Housing, Supportive Service Providers Brace for Federal Cuts

Organizations that provide housing assistance are tightening their purse strings and making plans for maintaining operations if federal funding dries up.

45 seconds ago - KSL

Conductor walks down platform next to Amtrak train at station in San Jose, California.

Op-Ed: Why an Effective Passenger Rail Network Needs Government Involvement

An outdated rail network that privileges freight won’t be fixed by privatizing Amtrak.

1 hour ago - Streetsblog USA

Aerial view of flooding during Hurricane Helene in North Carolina.

‘Quality Work, Fast’: NC Gears up for Homebuilding After Helene, Trying to Avoid Past Pitfalls

The state will field bids to demolish, repair and rebuild homes in the mountains. After struggles in eastern NC, officials aim to chart a different course.

2 hours ago - NC Newsline

Urban Design for Planners 1: Software Tools

This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.

Planning for Universal Design

Learn the tools for implementing Universal Design in planning regulations.