Middle Housing & ADU Regulations

Overview

In response to recent Washington State legislation, Clyde Hill is updating local development regulations to accommodate required Middle Housing and comply with new specifications for Accessory Dwelling Units (ADUs). This work is anticipated to be completed in June 2025, with public meeting review, discussion, and opportunities for public comment beginning in early 2025.

BackgroundIn 2023, the Washington State Legislature adopted House Bill (HB) 1110, which requires Washington cities to allow a broader range of 'middle' housing types in areas where predominantly detached single family homes exist. 

The City will also update regulations to comply with HB 1337, which requires cities to allow at least two accessory dwelling units on one lot in addition to the principal residential unit.

 

What Is Middle Housing?

Middle housing refers to homes that fall somewhere between detached single-family houses and large multifamily complexes, with two or more housing units per lot.  Middle housing can include duplexes, townhouses, courtyard housing, townhomes, and more. Along with ADUs, middle housing contributes to housing diversity and affordability.

Middle Housing


How Will Clyde Hill Be Affected?

Middle Housing
The City will be required to allow two middle-housing dwelling units per lot in all residentially-zoned areas. This is a change from the one single-family home + one ADU allowed currently. Like single-family homes in Clyde Hill, middle housing types will be required to comply with limits to building size, width, depth, and height. Clyde Hill may not establish design requirements for middle housing that are different from single-family housing.

Accessory Dwelling Units (ADUs)

Currently, Clyde Hill allows one ADU per lot, up to 900 sq. ft. The new rules will allow two ADUs per lot with a single-family home, up to 1,000 sq. ft. each, which can be attached or detached. Existing requirements on owner occupancy and door placement must be repealed to meet new state legislation. Height limits will remain the same at 25 feet.

Implementation
The City is not required to allow a combination of middle housing and ADUs on one lot. Allowable housing unit configurations in Clyde Hill will include:

  • Single Family Home + up to 2 ADUs (attached or detached)
  • Duplex
  • 2- Unit Stacked Flats
  • 2- Unit Cottage Housing
  • 2- Unit Courtyard Apartments

For more detailed information about each of the above middle housing types, including definitions, photo examples and conceptual site plan views, see our Middle Housing Types Examples (PDF) handout.
 

Engagement Opportunities

Staff provides regular updates on Middle Housing & ADU code update work to the City Council at their regular monthly meetings. Beginning in early 2025, the Council will review and discuss draft development regulations. Community members are welcome to provide public comment at these or any public meetings. See the 'Quick Links' section at the top right of this webpage for the latest drafts and informational materials.

The City anticipates hosting an event to share information about the project, answer questions, and gather feedback in the first quarter of 2025.  Check back closer to the date for more details.

A public hearing will be held in Spring 2025. Check back closer to the date for more details.

For additional questions or to provide any comments, please email Maia Knox, Assistant City Administrator, and the Council Land Use subcommittee: Councilmember Hachamovitch & Councilmember Olson.

 

Timeline

The City is working with consulting firm BHC to perform a Middle Housing analysis and recommend draft development regulations to the Clyde Hill City Council.

  • October 2024: Review community input around housing needs and preferences gathered as part of the Comprehensive Plan process. Review State guidance and model ordinances for complying with Middle Housing and ADA regulations. Prepare Middle Housing & ADU Gap Analysis (PDF) to summarize community input, requirements, and policy options for City Council.
  • November 2024: Share and discuss draft development regulations with the City Council Land Use Committee. Make draft code available to the public.
     
  • December 2024 - February 2025: Present draft development regulations to City Council for review and possible referral to Planning Commission. Hold community conversation with residents to share information about the project, answer questions, and gather feedback.
     
  • Spring 2025: Once the Planning Commission and/or Council have completed their review and held at least one public hearing, staff will submit the draft development regulations to the Department of Commerce for comment.
     
  • June 2025: City Council anticipates adoption of Middle Housing and ADU Ordinance at their June 10, 2025 regular meeting. The deadline for adoption is June 30, 2025.