Beginning October 1, 2021, SDCI will start establishing separate, regular addresses and building IDs for detached accessory dwelling units (DADUs). Even though DADUs are accessory structures by code, they are dwelling units that should have their own address for emergency response, utilities, and mailing. Project descriptions will clearly identify that the structure is accessory to another structure.
To establish these addresses, SDCI will create a separate DADU record as part of the application intake for your building permit. If the DADU is part of a larger development proposal, this record will be a dependent record to the building permit and will be reviewed along with the other structures on the site. If you are only building a DADU, it will be a standalone record. In both scenarios, the DADU will receive an assigned address and building ID by SDCI as part of the permit review beginning October 1.
For DADU applications that are in review and/or have been issued, applicants can request an address assignment for the DADU by filling out the last page on Tip 130, Addressing Review, and emailing it to SCI_Addressing@seattle.gov.