Snohomish County has some of the most generous shed rules in western Washington — rural properties can build up to 400 square feet without a permit, and even Urban Growth Areas (UGA) allow 200. But the rules split: UGA lots get 9-foot wall height limits while rural gets 11 feet, and setbacks range from 5 to 15 feet depending on your zone. Whether you're on 5 acres outside Granite Falls or a half-acre lot near Cathcart, here's what the county code actually says.
For unincorporated Snohomish County areas. Incorporated cities may have their own requirements.
| Shed Permit Rules | Urban (UGA) | Rural Areas |
|---|---|---|
| Max Shed Size (No Permit) | 200 sq ft | 400 sq ft |
| Max Shed Wall Height | 9 ft | 11 ft |
| Max Shed Height (Overall) | 25–35 ft (per zone) | 35–45 ft (per zone) |
| Setbacks (Side/Rear) | 5–15 ft (varies by zone) | 5–15 ft (varies by zone) |
| Setbacks (Front) | Per zone — check your parcel | Per zone — check your parcel |
“One-story detached accessory structures not used for human habitation (tool sheds, playhouses, similar uses) are exempt provided floor area within the outside perimeter of the exterior walls does not exceed 200 square feet (18.6 m2) and the sidewalls do not exceed nine feet in height measured from grade average.”
SCC 30.50.103(1)(a)(i)(A) — Permit Exemption (UGA) →
“One-story detached accessory structures not used for human habitation (tool sheds, playhouses, similar uses) are exempt provided floor area within the outside perimeter of the exterior walls does not exceed 400 square feet (37.2 m2) and the sidewalls do not exceed eleven feet in height measured from grade average.”
SCC 30.50.103(1)(a)(ii)(A) — Permit Exemption (Rural) →
“Eaves may extend a maximum of 24 inches past exterior walls unless encroaching into setbacks. Storage lofts allowed if area doesn't exceed one-third of building footprint; clear height not exceeding five feet for loft areas greater than 70 square feet. Plumbing permits required; heating systems prohibited in exempt accessory structures.”
SCC 30.50.103(1)(a)(i)(B–D) — Additional Exemption Rules →
Have questions about permits or zoning? We don't have all the answers, but we deal with this stuff regularly and can usually help you figure it out. Reach out with your address and we'll point you in the right direction.
Building codes and permit requirements are subject to change. Contact your local building department to verify current regulations before beginning your project.
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