Seattle Department of Construction & Inspections
Nathan Torgelson, Director
Small Efficiency Dwelling Units
What Is It?
We regulate small efficiency dwelling units (also known as micro-housing), congregate residences (group homes), and similar forms of development.
- Each small efficiency dwelling unit must have a minimum room size of 150 square feet and a full kitchen or kitchenette, and must meet the requirements in Director’s Rule 9-2017, Small Efficiency Dwelling Units.
- Generally, congregate residences are only allowed in urban villages and urban centers in these zones:
- Neighborhood Commercial 3 (NC3)
- Midrise multifamily (MR)
- Highrise multifamily (HR)
- Seattle Mixed (SM)
- Commercial (C1)
- Downtown zones
- Certain congregate residences, such as college dormitories and state licensed senior housing, are allowed in all zones that allow multi-family development.
Small efficiency dwelling units and congregate residences need to go through Design Review, based on the size of the development:
- 5,000 – 11,999 square feet: Streamlined Design Review
- 12,000 – 19,999 square feet: Administrative Design Review
- 20,000+ square feet: Design Review Board review
Read the Code
- Director's Rule 9-2017, Small Efficiency Dwelling Units
- SEDU Story Count for Natural Light
- SEDU Closets and Storage
- SEDU Minimum Yards & Courts Sizes for Natural Light
Proposed Changes
None