Middle Housing / HB 2001


Middle Housing

What is middle housing / HB 2001?

A new state law requires local code updates to increase opportunities for middle housing – buildings that provide living units for more than one household while historically similar in size or proportion to a detached house. Middle housing includes:

  • Duplex Duplex - two attached dwellings on a lot
  • TriplexTriplex - three attached dwellings on a lot 
  • Quadplex Quadplex - four attached dwellings on a lot 
  • Cottage Cluster Cottage clusters - a group of four or more detached dwellings around a common courtyard
  • Townhouse Townhouses - a dwelling in a row of two or more attached dwellings, each on its own lot

Middle housing was common in pre-1940s neighborhoods. Nestled among single detached homes, it offered housing variety for many incomes and needs. In communities that developed later, like much of unincorporated Washington County, whole neighborhoods of single detached homes gained popularity. As this trend grew, residential zoning laws often made it harder to develop middle housing. Often, people who couldn’t afford a typical detached house lost opportunities to live near good jobs, schools, services, recreation, social interests and loved ones. 

Middle housing in neighborhoods can give more people freedom to live where they want and improve choices for low and middle-income groups, smaller households, young adults, seniors and people whose housing options have been historically impacted by discrimination

Oregon's middle housing bill and rules 

House Bill (HB) 2001 is a 2019 Oregon law that boosts potential for middle housing. Oregon Administrative Rules (rules) direct local governments’ development of standards to meet the law. The bill and its rules expand property owners’ rights to build middle housing on sites where just one home might be seen today. The state expects local increases in housing choice to happen gradually, depending on housing markets and the growth of middle housing construction knowledge.

Large cities outside Metro, and counties and cities within Metro, must adopt standards to comply with state requirements by June 30, 2022. Inside the urban growth boundary (UGB) in residential districts where these jurisdictions allow single detached homes, they also have to allow:

  • A duplex on each lot or parcel 
  • Triplexes, quadplexes, townhouses and cottage clusters – Local jurisdictions can choose to set minimum lot sizes for these. If they do, minimums can’t be more than:
    • Triplex    5,000 square feet * 
    • Quadplex    7,000 square feet *
    • Cottage Cluster(s)    7,000 square feet
    • Townhouse: Townhouse lots within development averaging 1,500 square feet
    • *Exception: Higher minimum lot size allowed where minimum for one detached house is higher
  • Conversion of existing single detached dwellings to middle housing

The law requires “clear and objective” local regulations that don’t “discourage development of middle housing through unreasonable costs or delay.” The local approval process for a middle housing application is meant to be similar to the review for a detached house and can only regulate site and building design in specific ways. In most cases, maximum densities (limits on number of units per acre) can’t be applied. The state allows more local regulation in some cases, such as in protected natural areas or where development to meet adopted “master plan” requirements for a community hasn’t yet happened.   

Middle housing in Washington County

We have long allowed middle housing in residential districts, but not much has been built. Right now, we regulate middle housing by units per acre and limit certain types to certain districts. The approval process is more complicated for middle housing than it is for a single detached house, and restrictions for things like building placement and height differ. In some districts, unique requirements apply to middle housing. 

Under the bill and rules, we will have to change how our development code treats middle housing. Some differences:

The Washington County Board of Commissioners approved guiding principles that put community needs, collaboration and equity at the center of our work on code changes to expand middle housing options. HB 2001 uses the term “single-family.” That common term doesn’t suggest the full range of potential household types, and unrelated people or extended families sometimes face discrimination as a result. Like many jurisdictions we’ll propose code changes in the spirit of equity that will not use occupants to describe housing types (“single detached” instead of “single-family detached” home, for example). 

Where new middle housing
standards will apply

Middle Housing map

Click to enlarge 

We are studying:

  • Where middle housing may be more and less economically feasible to develop, and 
  • How potential policy and code changes could affect feasibility

We’ll update this page as the study continues. Please come back to learn more. 

County timeline for middle housing standards

  • Department of Land Conservation and Development Rulemaking: July 2020–January 2021

  • HB 2001 Code Assistance Project: October 2020–July 2021

  • HB 2001 Implementation: July 2020–June 30, 2022

    • Phase 1: Research & analysis scope project & outreach: July 2020–April 2021

  • Phase 2: Code concepts & Policy decisions: April 2021–September 2021 
Middle Housing timeline
Enlarge timeline
  • Phase 3: Code writing: September 2021–January 2022

  • Phase 4: Adoption process: January 2022–June 30, 2022

  • Public Outreach: July 2020–June 30, 2022

    • Website, Online open house and Outline involvement plan (incl. equity diversity and inclusion): July 2020–April 2021

    • Ongoing public involvement (TBD): September 2021–January 2022

    • Planning Commission Hearings and Board of Commissioners Hearings: January 2022–June 30, 2022


Oregon's problematic history of land use regulation 

Washington County is one of the most racially and ethnically diverse counties in Oregon. In February 2020, the County adopted an equity resolution that commits to dismantling long-standing systems, programs, policies and practices that may have historically created obstacles to the success of people of color, members of ethnic communities and any marginalized group. 

In Oregon, land use regulation has a long history of discrimination. Mid-1800s territorial laws and then a state constitution prohibited residents of color. Laws that banned, limited or revoked residency or land rights of non-whites continued impacting native, black, Chinese and Japanese people and others of color well into the next century. 

As years passed, zoning, deeds and covenants associated with residential development continued to limit where they could live (not only in Oregon but throughout the country). The civil rights movement of the 1960s spurred change through the Federal Fair Housing Act, but lingering impacts of past land use practices still affect many people’s housing options today.


Segregated by Design Zoning Matters
Watch Segregated by Design by Richard Rothstein, author of The Color of Law (~18 mins)   Watch Zoning Matters: How Land Use Policies Shape Our lives from the Urban Institute  (~3 mins)


Learn more:

Public Engagement 

Housing issues affect everyone. We’re developing a middle housing public engagement plan centered around equity, diversity and inclusion. If you have never participated in a county planning process, please think about it. We want to involve those who may be most impacted by changing policies We want to hear from people differing in household size, age, income, abilities, race, ethnicity, orientation, personal and professional experiences with housing and housing need. We want to hear from you.

We’ll update opportunities for involvement here. 

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Community feedback is an important part of developing our middle housing standards, and we want to hear from you! Subscribe for email updates or use the form below to comment or ask questions.