What's New? 

The Office of Planning and Development (OPCD) launched the ADUniverse website in September 2020. The ADUniverse features a gallery of pre-approved DADU designs, a step-by-step guide to the ADU process, and a search tool to identify the feasibility of adding an ADU to your property.

Pre-approved DADU plans

OPCD's gallery of pre-approved designs for backyard cottages is now live. Created by local designers and architects, these 10 building plans offer a faster, easier, and more predictable permitting process for creating a DADU. In most cases, you can get your permit in just 2-6 weeks. See How To Apply for a Detached Accessory Dwelling Unit Using a Standard Plan for more information about the permitting process.

Seattle's ADU Reform

In July 2019, Mayor Jenny Durkan signed legislation to remove regulatory barriers and make it easier for property owners to create accessory dwelling units (ADUs) in Seattle's single-family zones. The new ADU regulations took effect on August 8, 2019. 


Information about the new legislation is listed below: 


1. Check out this recent article on Crosscut by Jeff Cohen:

Is Seattle ready to take backyard cottages mainstream?


2. This new Seattle Times article regarding backyard cottages by Daniel Beekman:

Ruling could pave way for more mother-in-law units, backyard cottages in Seattle


3. Here is a link that discusses the current city council proposal and its goals:



4. The city has a nice summary at the bottom I have included for a quick glance: