Sammamish Zoning & Land Use Guide
Official references and local checks
Use the official references below to identify the rules that apply to your address, then confirm parcel-specific requirements with the local authority before filing an application.
Official references
- Population:
- 67,455
- County:
- King County
- State building code:
- WA State Building Code (based on 2021 IBC)(statewide default)
- State ADU law:
- Yes — 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).
- FEMA flood map:
- Search flood zones
- Planning department:
- City of Sammamish Community Development
- Municipal code:
- View code online
- Zoning map:
- View local zoning map
Before you apply
- Call the City of Sammamish Community Development: (425) 295-0500
- Search the municipal code for the chapter that covers your zoning district and proposed use.
- Use the local zoning map to look up your parcel's zoning designation before applying for a permit.
- Check FEMA flood zone for your parcel — flood-zone status changes setbacks, foundation requirements, and insurance.
- Check your HOA CC&Rs and recorded deed restrictions — they are common in Sammamish and frequently restrict ADUs, fences, and exterior changes beyond what zoning allows.
Key Zoning Facts
Sammamish is a city in Washington with approximately 65,892 residents, located in King County on the Sammamish Plateau. The city manages land use and development through its zoning code, administered by the Community Development Department. Sammamish's zoning divides the municipality into districts regulating permitted uses, building heights, lot sizes, setbacks, and density.
Sammamish 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
Sammamish is predominantly a residential community. The R-1 district requires a minimum lot size of 1 acre for estate-style development. The R-4 district allows approximately 4 units per acre with 9,000 square foot lots. The R-6 district allows 6 units per acre with 7,000 square foot lots. The R-8 district supports 8 units per acre with 4,500 square foot lots. All residential districts have a 35-foot height limit.
Limited commercial activity is served by the NB (Neighborhood Business) and CB (Community Business) districts.
ADU (Accessory Dwelling Unit) Rules
Sammamish 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). Contact the Community Development Department for current requirements including size limits, setbacks, and permitting procedures.
Development Process
Development in Sammamish generally requires obtaining the appropriate permits. The process typically involves:
- Zoning Verification — Confirm that your proposed use is permitted in the applicable zoning district
- Site Plan Review — For commercial and multi-family projects, submit a site plan for review
- 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.
Key Considerations
Before starting any development project in Sammamish, 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 Community Development at (425) 295-0500 for pre-application guidance
Disclaimer: This guide provides general information about zoning in Sammamish and should not be relied upon as legal advice. Zoning codes are subject to change. Always verify current regulations with the City of Sammamish or the municipal code before making development decisions.
Regulatory Layers That Apply in Sammamish
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
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.
Statewide Context (Washington)
Local data for Sammamish is limited. The following state-level facts apply across Washington and are inherited by this page until city-specific details are verified.
- State Building Code
- WA State Building Code (based on 2021 IBC)
- State ADU Preemption
- Yes — state law overrides local rules
- Coastal Zone
- Yes
- Wildfire Zones
- Yes
ADU Rules in Sammamish
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 City of Sammamish Community Development.
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 Sammamish permit information →Official Sources
City-specific