What’s on a site in King County, WA?
Type any address in King County and Design Workbench pulls the parcel, zoning, flood, fire, faults, soils, seismic, climate and weather history from public sources in about twenty seconds, then runs the calculators on it. Free, no account.
Or open the map on King County and click a lot.
What the Workbench shows for sites in King County
| Parcel and tax ID | Washington statewide Current Parcels (WaTech, from the county assessors), with the parcel outline on the map. |
|---|---|
| Zoning | Zoning code, height and FAR limits where the city or county publishes open zoning data, with a link to the source. |
| Flood | FEMA National Flood Hazard Layer zone at the point, and whether it is a Special Flood Hazard Area. |
| Fire and geologic hazards | USGS faults nearby and the national wildfire and fire-history layers; state hazard zone maps are mostly California only. |
| Seismic design values | At the county centre (47.4906, -121.8340), Risk Category II, default site class, ASCE 7-22: Seismic Design Category D, SDS 0.99, SD1 0.57 (SS 1.31, S1 0.37). The Workbench recomputes these for the exact address and your risk category and site class. |
| Climate zone | IECC / ASHRAE 169 zone 4C (Marine) for King County, which sets the energy code envelope table and the vapor retarder rule. |
| Wind and snow | Entered by hand in the calculators; the Workbench does not call the ASCE servers. The wind pressure and window PG calculators run from your basic wind speed. |
| Weather history | Wind-driven rain, storm archive, atmospheric rivers and active fires for the West Coast; weather on a grid of about 30 miles. |
| Calculators | Development yield and construction type, code analysis and egress, fire separation, wind pressures, components and cladding with window PG, ground snow, design-storm rainfall, roof drainage, roof and wall condensation, energy code envelope table, embodied carbon, grading, stormwater, wetlands, cladding seismic forces, sea level and heat. |
| Files | A site report, a CAD base file (DXF) and an IFC model that opens in Revit, with the lot, the neighbours and the yield massing by storey. |
Seismic values from the USGS ASCE 7-22 web service; climate zone from the DOE county assignment; county centre and area from the 2024 Census Gazetteer (2,115.696 sq mi of land). Fetched 2026-10-31. Values at a centre point are not values for your site: look the address up.
Permits and codes in King County
| Who issues the permit | Not found on an official page |
|---|---|
| Adopted building code | 2021 Washington State Building Codes for applications complete on or after March 15, 2024; King County amendments in KCC Title 16 Code page |
Read on the department's page on 2026-10-31. Hours, counters and portals change; call before you go. The Workbench shows the same card when you open a site here.
Other places in Washington
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