Building Setbacks & Zoning in King County, WA (2026)

3 county-level rules, plus city-specific rules for 6 cities in King County, Washington.

Verified from official government sources

Note: These county rules apply to unincorporated areas of King County. If you live within an incorporated city, that city's own rules apply: see the city list below.

Setback Rules

Unincorporated King County sets a 10-foot minimum street setback and 5-foot interior setback in the R-4 through R-48 zones, with wider setbacks in UR and R-1.

King County Yard Setback Minimums by Zone

Some Restrictions

King County Code § 21A.09H.030

21A.09H.030 Residential zones - density and dimensional standards... Urban Area Residential Density and Dimensional Standards... STANDARDS UR R-1 R-4 R-6 R-8 R-12 R-18 R-24 R-48 ... Minimum Street Setback (5) 30 ft (16) 20 ft (16) 10 ft 10 ft 10 ft 10 ft 10 ft 10ft 10 ft ... Minimum Interior Setback (5) 5 ft (16) 5 ft (16) 5 ft 5 ft 5 ft 5 ft 5 ft 5 ft 5 ft

Full ordinance details →Official source ↗

Structure Height Limits

In unincorporated King County's urban single-family zones (R-4 through R-8), homes are capped at a 35-foot base height, extendable to 45 feet only by adding one foot of setback for every foot built above base.

King County Residential Structure Height Limits

Some Restrictions

King County Code § 21A.09H.030

STANDARDS R-4 R-6 R-8 R-12 R-18 R-24 R-48 Base Height (11a) 35 ft 35 ft 35 ft 60 ft 60 ft 60 ft 60 ft Maximum Height (11b) 45 ft (7) 45 ft (7) 45 ft (7) 65 ft (3) 80 ft (3) 80 ft (3) 80 ft (3) "7. This maximum height is allowed... c. for a structure that provide one additional foot of street and interior setback for each foot above the base height."

Full ordinance details →Official source ↗

Lot Coverage Limits

Unincorporated King County caps impervious surface, pavement, roofs, decks, by zone under Code § 21A.09H.030: 55% in R-4, 70% in R-6, 75% in R-8, and up to 90% in R-48, measured per lot.

King County Impervious Surface Limits

Some Restrictions

King County Code § 21A.09H.030

The impervious surface maximum applies to each individual lot. Impervious surface does not include access easements serving neighboring property and driveways to the extent that they extend beyond the street setback due to location within an access panhandle or due to the application of King County Code requirements to locate features over which the applicant does not have control.

Full ordinance details →Official source ↗