Seattle Zoning & Land Use Guide
Key Zoning Facts
Seattle is the largest city in Washington with approximately 737,015 residents, located in King County. The city manages land use and development through its zoning code, administered by the Seattle Department of Construction & Inspections (SDCI). Seattle's zoning divides the municipality into districts regulating permitted uses, building heights, lot sizes, setbacks, and density.
Seattle follows the Washington State Building Code (WAC 51-50/51), which is based on the International Building Code (IBC) and International Residential Code (IRC).
Primary Zoning Districts
Seattle's zoning code includes several Neighborhood Residential (NR) districts (formerly designated "Single-Family" or "SF" districts and renamed by Ordinance 126509 in 2021). NR3 (formerly SF 5000) requires a minimum lot size of 5,000 square feet with a 30-foot height limit and setbacks of 20 feet (front), 5 feet (side), and 25 feet (rear). NR2 (formerly SF 7200) requires 7,200 square foot minimum lots, and NR1 (formerly SF 9600) requires 9,600 square foot minimum lots, both with similar height and setback standards.
The LR1 and LR2 (Lowrise) districts accommodate multifamily housing including townhouses and apartments at varying densities. Commercial needs are served by the NC (Neighborhood Commercial), C1 (Commercial 1), and C2 (Commercial 2) districts, which support retail, services, and mixed-use development. The IG (Industrial General) district provides for manufacturing and warehousing uses.
ADU (Accessory Dwelling Unit) Rules
Seattle allows ADUs (Accessory Dwelling Units). Under Washington state law HB 1337 (2023), cities are required to allow ADUs, with up to 2 ADUs permitted per lot in most areas. This applies to cities planning under the Growth Management Act (which includes most urban Washington cities). Seattle allows both attached and detached ADUs. Contact SDCI for current requirements including size limits, setbacks, owner-occupancy rules, and permitting procedures.
Development Process
Development in Seattle generally requires obtaining the appropriate permits from SDCI. The process typically involves:
- Zoning Verification — Confirm that your proposed use is permitted in the applicable zoning district
- Pre-Application Conference — For larger projects, meet with SDCI staff for guidance
- Design Review — Some projects require design review board approval
- Building Permit — Apply for a building permit with construction documents
- Inspections — Schedule required inspections during construction
- Certificate of Occupancy — Obtain final approval before occupying the structure
For projects that do not conform to existing zoning, property owners may need to seek a variance, special exception, or rezoning through the local board of zoning appeals or planning commission.
Key Considerations
Before starting any development project in Seattle, property owners should:
- Verify the zoning classification of their property
- Review setback, height, and lot coverage requirements for their specific district
- Check for any overlay districts or special regulations
- Determine if the property is in a flood zone using FEMA's flood map service
- Confirm whether HOA covenants or deed restrictions apply
- Contact SDCI at (206) 684-8850 for pre-application guidance
Disclaimer: This guide provides general information about zoning in Seattle and should not be relied upon as legal advice. Zoning codes are subject to change. Always verify current regulations with the City of Seattle SDCI or the municipal code before making development decisions.
Regulatory Layers That Apply in Seattle
Your property is subject to ALL of these regulatory layers. Each one can impose additional requirements beyond the others.
Federal
- FEMA flood mapping: check parcel-specific flood-zone status
- View FEMA Flood Map
State — Washington
- Building Code: WA State Building Code (WAC 51-50/51)
- State ADU Override: Yes (WA HB 1337 (2023) requires cities to allow ADUs; 2 ADUs per lot in most areas)
County — King County
- Role: County-level property records, tax assessment, unincorporated area planning
City / Municipal
The municipality's zoning ordinance, building-code enforcement, and local permits form the primary local layer of land-use regulation for your property.
Overlay Districts
No overlay districts identified.
Private Restrictions
- Private covenants, deed restrictions, condominium rules, or association rules can impose requirements beyond zoning.
- Check HOA CC&Rs and deed restrictions for additional requirements.
Primary Zoning Districts
- Max Height
- 32 ft ordinary maximum; 42 ft for specified qualifying development
- Front Setback
- 15 ft for 1–2 units; 10 ft for 3+ units
- Side Setback
- 5 ft average / 3 ft minimum; some small frequent-transit lots use 3 ft
- Rear Setback
- 15 ft for 1–2 units or 10 ft for 3+ units when no alley; 0 ft at qualifying alley lot line
ADU Rules in Seattle
State law (statewide context, not city-specific):
Washington HB 1337 (2023, effective July 23, 2023) requires cities and counties planning under the Growth Management Act to allow at least two accessory dwelling units per lot in zones that permit single-family homes within urban growth areas. The law limits impact fees on ADUs, prohibits owner-occupancy requirements, and requires that ADUs of at least 1,000 sq ft be allowed. HB 1110 (2023) separately legalized middle housing (duplexes through sixplexes depending on city size).
For local size, setback, and parking specifics, contact the Seattle Department of Construction & Inspections (SDCI).
Permit Costs & Timelines
Check Current Permit Fees & Timelines
Permit fees and review times can vary by project type, scope, valuation, and required approvals. Check the current schedule with the local permitting authority before filing.
Check current Seattle permit information →Official Sources
City-specific