How to Roll Existing Projects Forward Using New Zoning Regulations for ADUs and Middle Housing

What’s Happening?

On June 30, 2025, Seattle implemented the HB1337 and HB1110 Compliance Bills (Ordinances 127211 and 127219), proposed by Mayor Harrell and adopted by the City Council. These Land Use Code changes align with state laws, increase housing supply, and diversify housing options in residential zones. The changes create a flexible framework to address Washington’s housing shortage, estimated at 140,000–250,000 units. These changes reduce barriers to constructing Accessory Dwelling Units and other “Middle Housing” types. The legislation supports population growth, reduces urban sprawl, and enhances housing access in Seattle.

Many applicants have been asking if it is possible to utilize the new regulations for their existing project without having to withdraw their current application and submit a new permit application. In some situations, the answer is yes. SDCI has created a Statement of Intent to facilitate these requests. If your project is currently under review or under construction, email your completed and signed Statement of Intent to your zoning reviewer along with your current and proposed site plans.

Which Projects Qualify?

 Below are the general scenarios that may qualify.

• Existing permit applications in review but not yet issued:
  
  • Changes qualify if the overall scope of the change remains subject to the Seattle Residential Code (SRC).
    • You elect to abandon your vesting to the land use codes in effect at the time of your original permit application and still remain vested to the SRC of your original permit application. You must acknowledge that the project will not vest to the land use codes until the day the permit is issued. If new buildings are proposed, you must submit a new construction permit application, which will be subject to the latest version of the SRC and land use codes.
    • If you change your permits that are under review, you may be charged additional fees according to the Fee Subtitle that was in effect when the original application was accepted and Director’s Rule 2-2021.
      
      
• Revisions to an issued permit that has not expired:
  • Revisions qualify if the overall scope remains subject to the SRC
    • Your project will remain vested to the version of the SRC that it was originally subject to, but the scope of change proposed in the revision will be subject to land use codes in effect when the revision is approvedIf new buildings are proposed, each will require a new building permit application subject to the current version of the SRC and land use codes
    • If you make revisions to permits, you’ll be charged fees according to the Fee Subtitle in effect when the original application was accepted and Director’s Rule 2-2021
      
      
• You plan to add buildings or make alterations to an existing building or site and the permit has expired or closed:
  • If your project is no longer active or has been completed, and you wish to modify what was built or add new structures to the lot, a new building permit application is required
  • Your new permit will be subject to the current Building and Construction Codes, and Land Use Codes