6329 20TH AVE NE

• Size1,000 sq ft with up to 2 bedrooms, or 1,200 sq ft with 3 or more. Source 2
• Height32 ft, or 42 ft when a tree, deep front yard, or stacked-flat condition is met. Source 1
• Setback5 ft, or 0 ft where the lot line abuts an alley. Source 1
• ParkingNone required for an ADU. Source 2
• OwnerDoes not have to live on the lot. Source 5
• SaleAn ADU can be sold as a condo. It cannot be subdivided off the main home. Source 2 Source 1
• Coverage50% of the lot, less where critical areas apply. Source 1

The primary house is typically 15 ft from the front with one or two homes, or 10 ft with three or more. Rear yards follow the same pattern unless the rear line is an alley (0 ft). Side setbacks are a 5 ft average with a 3 ft minimum. Buildings stay 5 ft apart. Source 1

Not counted in the ADU size cap: Up to 250 sq ft of an attached garage; Stories or portions of stories that are underground; Up to 35 sq ft of long-term bicycle parking. Seattle repealed the old 3,200 sq ft minimum for a detached ADU. An ADU does not need its own minimum lot size. No off-street parking is required for an ADU. Other homes on the lot generally need one space per two homes, with exceptions within a half mile of a major transit stop and for homes of 1,200 sq ft or less. Source 2 Source 1

Seattle already allows unit lots: they can be sold separately, but they stay tied to the parent site for redevelopment. New parent lots cannot be smaller than 5,000 sq ft. Unit lots have no minimum size. An ADU cannot be separated from the principal home through subdivision. Source 1 Source 6