Cities · Washington
Can I build a backyard home in my city?
Since 2023, Washington law lets most city lots hold up to two more homes. Every city writes its own rules on top: how big, how tall, how close to the line. Pick yours. Each page is read from that city’s code, with the section cited, and ends with a free report on your own lot.
Snohomish County
11 places
City
Edmonds
- Per lot
- 2 on a detached single-family lot
- Max size
- 1,200 sq ft
- Height
- 24 ft in all zones
City
Everett
- Per lot
- No limit in NR, UR and MU zones
- Max size
- Under 1,000 sq ft by definition
- Height
- Detached: 18 ft on a non-alley NR lot, 24 ft on an alley lot
City
Lake Stevens
- Per lot
- 2
- Max size
- 1,000 sq ft gross floor area
- Height
- 35 ft
City
Lynnwood
- Per lot
- 2
- Max size
- 1,000 sq ft
- Height
- 35 ft
City
Marysville
- Per lot
- 2 per single-family lot
- Max size
- 1,000 sq ft or 50% of the residence, whichever is greater, capped at 1,400 sq ft
- Height
- 30 ft
City
Mill Creek
- Per lot
- 2
- Max size
- 1,000 sq ft
- Height
- 35 ft
City
Mountlake Terrace
- Per lot
- 2 on any lot, and they do not count toward maximum density
- Max size
- 200-1,000 sq ft excluding garage
- Height
- Zone height applies
City
Mukilteo
- Per lot
- Maximum 2 per single-family lot
- Max size
- 1,000 sq ft habitable
- Height
- 24 ft
City
Snohomish
- Per lot
- 2
- Max size
- No maximum
- Height
- 30 ft
Unincorporated
Snohomish County (unincorporated)
- Per lot
- 2 per urban single-family lot
- Max size
- 1,200 sq ft of floor area, excluding garages, porches, unheated storage and unfinished basements
- Height
- The zone height: 30 ft in R-9,600 / R-8,400, 35 ft in R-7,200
City
Bothell
- Per lot
- 2
- Max size
- 1,200 sq ft
- Height
- 30 ft
King County
10 places
City
Bellevue
- Per lot
- Up to 2
- Max size
- 1,200 sq ft
- Height
- 24 ft
City
Kenmore
- Per lot
- 2 per lot, attached or detached in any combination
- Max size
- Attached 1,000 sq ft
- Height
- 35 ft
City
Kirkland
- Per lot
- 2 per single-family dwelling
- Max size
- 1,200 sq ft gross floor area
- Height
- The zone’s single-family height
City
Redmond
- Per lot
- 2 per lot
- Max size
- 1,000 sq ft
- Height
- 38 ft
City
Renton
- Per lot
- 2 per legal lot
- Max size
- 1,000 sq ft
- Height
- 24 ft
City
Seattle
- Per lot
- 2 per lot, any combination, including two DADUs
- Max size
- 1,000 sq ft
- Height
- 32 ft in NR/RSL zones
City
Shoreline
- Per lot
- 2 per lot, not subject to base density
- Max size
- 1,200 sq ft
- Height
- Zone base height, 23-35 ft in residential zones
City
Woodinville
- Per lot
- Maximum 2 ADUs per parent lot
- Max size
- 300-1,500 sq ft habitable
- Height
- 35 ft
Unincorporated
King County (unincorporated)
- Per lot
- Urban growth area: up to 2. Rural: 1. Forest: none
- Max size
- 1,000 sq ft heated + 1,000 sq ft unheated
- Height
- The zone’s base height: 35 ft in R-4 / R-6 / R-8
City
Bothell
- Per lot
- 2
- Max size
- 1,200 sq ft
- Height
- 30 ft
Pierce County
2 places
City
Tacoma
- Per lot
- 2 per lot
- Max size
- 1,000 sq ft of living area
- Height
- Zone height
Unincorporated
Pierce County (unincorporated)
- Per lot
- Urban growth area: 2 per lot of record. Outside the UGA: 1
- Max size
- 1,000 sq ft in the UGA
- Height
- Not above the main house
Not on the list?
The state floor applies everywhere inside a city’s growth area.
At least two units per lot, at least 1,000 square feet, no owner-occupancy rule, condominium sale allowed. The report starts from the floor and reads your city’s code on top.