Seattle ADU & DADU permit tracker
Follow accessory dwelling unit permits across Seattle, compare attached ADUs with detached backyard cottages, and see where new small-scale housing activity is concentrating.
These are matching permit records, not a count of guaranteed completed dwellings. One property or project can have multiple related permits.
Source data updated through Aug 1, 2026.
ADU and DADU permits by year
Grouped by issue date when available, otherwise application date.
Seattle neighborhoods with the most ADU activity
Recent Seattle ADU and DADU permits
| Permit | Type | Address | Neighborhood | Status | Value | Date |
|---|---|---|---|---|---|---|
| 7124215-CN | DADU | 2011 NOB HILL AVE N, SEATTLE, WA | Queen Anne | active | $145K | Jul 29, 2026 |
| 7112234-CN | DADU | 4827 49TH AVE SW, SEATTLE, WA | West Seattle | active | $771K | Jul 27, 2026 |
| 7092853-CN | ADU | 326 N 125TH ST, SEATTLE, WA | Broadview | active | $21K | Jul 23, 2026 |
| 7154747-CN | ADU | 3510 W COMMODORE WAY, SEATTLE, WA | Magnolia | active | $175K | Jul 23, 2026 |
| 7154486-CN | DADU | 9032 3RD AVE NW, SEATTLE, WA | Greenwood | completed | $165K | Jul 23, 2026 |
| 7138346-CN | DADU | 9032 3RD AVE NW, SEATTLE, WA | Greenwood | pending | $40K | Jul 23, 2026 |
| 7122874-CN | DADU | 5521 34TH AVE NE, SEATTLE, WA | Ravenna | pending | $225K | Jul 23, 2026 |
| 7100311-CN | DADU | 3815 S SULLIVAN ST, SEATTLE, WA | Rainier Valley | active | $203K | Jul 22, 2026 |
| 7109996-CN | ADU | 13341 31ST AVE NE, SEATTLE, WA | Pinehurst | active | $13K | Jul 21, 2026 |
| 7145261-CN | DADU | 12724 PHINNEY AVE N, SEATTLE, WA | Broadview | active | $240K | Jul 20, 2026 |
| 7137494-CN | DADU | 12724 PHINNEY AVE N, SEATTLE, WA | Broadview | active | $240K | Jul 20, 2026 |
| 7138484-CN | DADU | 1708 S ORCAS ST, SEATTLE, WA | Georgetown | active | $238K | Jul 20, 2026 |
| 7136352-CN | DADU | 9715 DAYTON AVE N, SEATTLE, WA | Greenwood | active | $186K | Jul 20, 2026 |
| 7127737-CN | DADU | 11748 SAND POINT WAY NE, Seattle, WA | Lake City | pending | $4K | Jul 20, 2026 |
| 7058576-CN | DADU | 8449 46TH AVE S, SEATTLE, WA | Rainier Valley | active | $205K | Jul 20, 2026 |
| 7121918-CN | DADU | 11011 FREMONT AVE N, SEATTLE, WA | Greenwood | active | $435K | Jul 17, 2026 |
| 7131746-CN | ADU | 9606 MARY AVE NW, SEATTLE, WA | Crown Hill | active | $461K | Jul 16, 2026 |
| 7131747-CN | ADU | 9602 MARY AVE NW, SEATTLE, WA | Crown Hill | active | $477K | Jul 16, 2026 |
| 7116067-CN | ADU | 9608 MARY AVE NW, SEATTLE, WA | Crown Hill | active | $473K | Jul 16, 2026 |
| 7131748-CN | ADU | 9604 MARY AVE NW, SEATTLE, WA | Crown Hill | active | $477K | Jul 16, 2026 |
ADU vs. DADU
ADU is the broader term for an accessory dwelling unit associated with a primary home. It can be inside, attached to, or converted from part of an existing structure.
DADU means detached accessory dwelling unit. In Seattle records it may also appear as a detached ADU or backyard cottage.
How the tracker works
Building Seattle searches public permit descriptions for explicit ADU terminology, classifies detached projects separately, and aggregates results by year and neighborhood. A permit mentioning both attached and detached units is classified as DADU.
Declared permit values and housing-unit fields are presented as reported and may be incomplete or revised during review.
Using ADU permit activity
Homeowners can see the kinds of projects moving through Seattle review. Contractors and designers can identify neighborhoods with sustained accessory-dwelling demand. Researchers can track how small-scale infill contributes to Seattle's housing pipeline.
Raw tracker data is available at /api/adu-dadu. Source records come from Seattle Department of Construction and Inspections permit data.