Major Changes to Washington's Housing Laws

New townhomes | Photo: Steve Butler

Several significant housing and land use bills were passed by the Washington State Legislature during this year’s legislative session and signed into law by Governor Inslee, causing some observers to call 2023 “the Year of Housing” in our state. These bills are intended to expand the state’s housing supply and help address the ongoing affordable housing crisis.

Two of the more significant bills deal with “missing middle” housing (E2SHB 1110) and accessory dwelling units (EHB 1337). In short, these two bills require many local governments to revise their regulations to allow for a greater number and increased types of housing in areas traditionally dedicated to single-family detached housing. Both bills take effect on July 23, 2023, but local governments are not required to update their local regulations to be in compliance until six months after their periodic comprehensive plan update. However,  local government may revise its regulations sooner than the statutory deadline if desired.

This blog post will summarize those two bills.

Middle Housing Bill – E2SHB 1110

Middle housing (also called “missing middle” housing) refers to those housing types between single-family residences and mid-rise, multi-family development. Middle housing types included in the new state law are duplexes up to sixplexes, townhouses, stacked flats, courtyard apartments, and cottage housing.

Image © Opticos Design, Inc. | For more information visit www.missingmiddlehousing.com.

E2SHB 1110 requires designated Growth Management Act (GMA) planning cities, within 6 months after their periodic update due date, to allow certain minimum densities for middle housing. It does not apply to counties or unincorporated areas.

The Department of Commerce’s E2SHB 1110 fact sheet identifies 77 cities that this legislation applies to currently, based on 2020 U.S. Census data and Commerce’s best understanding, divided into three tiers. The fact sheet outlines the requirements as follows:

Middle housing types: City zoning codes must allow at least six out of the nine of listed types of middle housing:

1. Duplexes
2. Triplexes
3. Fourplexes
4. Fiveplexes
5. Sixplexes
6. Townhouses
7. Stacked flats
8. Courtyard apartments
9. Cottage housing

Other major provisions of the new missing middle housing bill include:

• Alternate density requirement: A city may choose to limit implementation of the density requirements to 75% of lots that are primarily dedicated to detached single-family houses, subject to specific conditions included in the new state law.
• Exceptions to density requirements: There are a very limited number of exceptions where a municipality does not need to accommodate middle housing, such as for lots designated with critical areas and their buffers.
• Adequate water and public sewer: Density requirements can be reduced in lots within a city that don’t have adequate water supply or public sewer service.
• Required parking: There are restrictions on how much on-site parking can be required, with a sliding scale for smaller-sized lots. No on-site parking standards may be applied to middle housing located within a half-mile of a major transit stop.
• Design review: If design review for residential development is required locally, it can only be administrative review (i.e., conducted by staff, and not by an appointed design board) for middle housing, with the use of clear design standards that are not more restrictive than those required for detached single-family houses. Please note that ESHB 1293 establishes a requirement for clear and objective design review standards for the exterior design of new development (beyond that covered by E2SHB 1110).
• SEPA exemption: A State Environmental Policy Act (SEPA) categorical exemption is established for regulations that remove parking requirements for new middle housing development projects.
• Implementation extensions: This bill provides process and criteria for extensions of implementation when requested by a local government.
• Technical assistance: The Department of Commerce is tasked with providing guidance, a model ordinance, and other related assistance to local governments. Commerce has begun by publishing a Fact Sheet for Implementing E2SHB 1110, which includes answers to local government questions and will be updated over time.

ADU Bill – EHB 1337

Accessory dwelling units (ADUs) are small, self-contained residential units located on the same lot as an existing single-family home. An ADU has all the basic facilities needed for day-to-day living, such as a kitchen, sleeping area, and a bathroom, and may be either attached to or detached from the primary residence.

EHB 1337 requires all GMA-planning local governments – regardless of population and including counties (unincorporated urban growth areas) as well as cities – to revise their regulations as needed to conform with the following new requirements, within 6 months after their periodic update due date, as follows:

• Minimum number of ADUs per lot: Two ADUs per lot must be allowed in all GMA urban growth areas, in addition to the principal unit, for lots that meet the minimum lot size required for the principal housing unit. Local regulations must permit ADUs to be attached, detached or a combination of both types. In addition, a conversion of an existing structure, such as a detached garage, must be allowed.
• Maximum ADU size standard: Local governments may not require ADUs to be smaller than 1,000 gross square feet in size.
• Dimensional standards: A local government may not impose setback requirements, yard coverage limits, tree retention mandates, or restrictions on entry door location that are more restrictive than those required for the principal unit.
• Street improvements: A local government may not require street improvements as a condition of permitting accessory dwelling units.
• Owner occupancy: A local government may not require owner occupancy for a principal unit or ADUs.
• Condominium sales: Local governments may not prohibit the sale or other conveyance of a condominium unit independently of a principal unit solely on the grounds that the condominium unit was originally built as an ADU.
• Design review: Local governments may not impose aesthetic standards or requirements for design review that are more restrictive for ADUs than those for principal units. Please note that ESHB 1293 establishes a requirement for clear and objective design review standards for the exterior design of new development (beyond that covered by EHB 1337).
• Required parking: There are restrictions on how much on-site parking can be required, with a sliding scale for smaller-sized lots. No on-site parking standards may be applied to ADUs located within a half-mile of a major transit stop.
• Impact fees. Impact fees for ADUs are limited to no more than 50% of those assessed to the principal housing unit.
• Common Interest Communities: After July 23, 2023, new “Common Interest Communities” (for example, a new subdivision with a homeowners association) are prohibited from adopting covenants, conditions, and restrictions (commonly called “CC&Rs”) that would limit the construction of ADUs on any lot. Existing CC&Rs, however, are not impacted by the new law and may remain in effect.

Conclusion

 If you are subject to the requirements of one or both bills, it is highly recommended that you start early to develop your development standards. It could likely take nine to twelve months to create and adopt the necessary changes to your middle housing and ADU regulations, so do not wait until your comprehensive plan has been adopted before starting work on any required land use regulatory revisions.

The summaries included in this blog post do not cover every aspect of the two bills. More details may be found in the resources linked below. There were also a number of other significant housing and land use bills that were recently passed and signed into law, including 2SSB 5412. MRSC will be writing blog posts that summarize those bills over the next few weeks.

I would like to thank Anne Fritzel and Dave Osaki with the Washington Department of Commerce for their assistance with this blog post.

Other Resources

Middle Housing

• Department of Commerce: Middle Housing in Washington – includes E2SHB fact sheet
• MRSC: Missing Middle Housing
• Makers Architecture + Design: How Washington’s Middle Housing Legislation Applies in Your Community – Very detailed article about HB 1110.

• Department of Commerce: Guidance for ADUs in Washington State – Draft guidance as of May 15, 2023
• MRSC: Accessory Dwelling Units