Seattle, WA Building Setbacks & Zoning: Setback Rules (2026)
Key Facts
- Front setback (1-2 units)
- 15 feet
- Front setback (3+ units)
- 10 feet
- Rear setback
- 10-15 feet; none if abutting an alley
- Side setback
- 5 feet average, 3 feet minimum
- Governing section
- SMC 23.44.090, Table A
Summary
SMC 23.44.090's Table A sets Neighborhood Residential front setbacks at 15 feet for lots with one or two units and 10 feet for three or more, rear setbacks of 10-15 feet (waived at an alley), and side setbacks averaging 5 feet with a 3-foot minimum.
Required setbacks in Neighborhood Residential zones. Front: Lots with one or two dwelling units: 15 feet; Lots with three or more dwelling units: 10 feet. Rear: Lots with one or two principal dwelling units not abutting an alley: 15 feet; Lots with three or more principal dwelling units not abutting an alley: 10 feet; Lots under 5,000 square feet within frequent transit service areas: 5 feet; If the rear setback abuts an alley, no rear setback is required. Side: Lots under 5,000 square feet within frequent transit service areas: 3 feet; All other lots: 5 feet average, 3 feet minimum.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Municipal Code: Supplement 44 Update 1).
Full Breakdown
090 sets the baseline yard setbacks for Seattle's Neighborhood Residential zones. Front setbacks run 15 feet for lots with one or two dwelling units and 10 feet for lots with three or more. Rear setbacks are 15 feet for one- or two-unit lots not abutting an alley, 10 feet for three-or-more-unit lots not abutting an alley, and drop to 5 feet on lots under 5,000 square feet within a frequent transit service area; no rear setback at all is required where the rear line abuts an alley.
Side setbacks average 5 feet with a 3-foot minimum on most lots, tightening to a flat 3 feet on lots under 5,000 square feet in frequent transit areas. A footnote gives lots fronting the landmark Queen Anne Boulevard right-of-way a 20-foot front setback (or the average of neighboring setbacks, whichever is less), reduced further on slopes over 35 percent. 53 street standards. 4.
Violations & Fines
Constructing a principal structure closer to a lot line than Table A for SMC 23.44.090 allows, without qualifying for one of the enumerated encroachments in subsection E, F, or H, is a zoning setback violation; SDCI will deny or condition the building permit and can require the applicant to move or reduce the structure to restore the required yard.
Frequently Asked Questions
How far must a house sit from the front property line in Seattle?
Is a rear setback required next to an alley?
What is the minimum side setback in Seattle's residential zones?
Sources & Official References
Other rules in Seattle
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Setback Rules in Nearby Cities
How other cities in King County handle setback rules.