Shed / Storage Building Permit in Seattle (2026)
Shed / Storage Building permit requirements, fees, and process for Seattle, WA. Find out if you need a permit and how to apply.
Shed / Storage Building permit requirements in Seattle, WA are conditional depending on project scope.
A Shed / Storage Building permit may be required depending on project scope in Seattle, WA. The Seattle Department of Construction and Inspections (SDCI) handles permit applications for Seattle. Below you will find the current thresholds, fees, and process for obtaining a shed / storage building permit in Seattle.
When Is a Permit Required?
When a Shed / Storage Building Permit Is Required in Seattle: Permit not required for sheds under 120 sqft in single-family zones (Seattle specific); permit required for sheds over 120 sqft or with utilities
Permit Fees
Shed / Storage Building Permit Fees in Seattle: $150–$400. Estimated timeline: 2-4 weeks.
Estimated timeline: 2-4 weeks
How to Get a Shed / Storage Building Permit in Seattle
Verify whether your project meets the permit threshold in Seattle: Permit not required for sheds under 120 sqft in single-family zones (Seattle specific); permit required for sheds over 120 sqft or with utilities.
Prepare your permit application and plans. Contact the Seattle Department of Construction and Inspections (SDCI) at https://www.seattle.gov/sdci for required documentation.
Submit your application online at https://cosaccela.seattle.gov/portal/welcome.aspx or in person at the Seattle Department of Construction and Inspections (SDCI).
Pay the permit fee: $150–$400.
Wait for plan check approval. Estimated timeline: 2-4 weeks.
Schedule required inspections through https://cosaccela.seattle.gov/portal/welcome.aspx. All inspections must pass before project is finalized.
Important: Seattle allows accessory structures under 120 sqft without a permit in SF zones, provided they meet setback requirements. Structures over 120 sqft, over 8 ft tall, or with plumbing/electrical require permit. Must be located within rear or side yard — not in front yard. SMC 23.44.025.
Seattle Department of Construction and Inspections (SDCI)
Phone: (206) 684-8850
Website: https://www.seattle.gov/sdci
Online Permits: https://cosaccela.seattle.gov/portal/welcome.aspx
Hours: Mon-Fri 8:00am-4:30pm (permit center)
Frequently Asked Questions
Can I build an ADU (backyard cottage) in Seattle?
Yes. Seattle is one of the most ADU-friendly cities in the US. You can build both a Detached ADU (backyard cottage/DADU, up to 1,000 sqft) and an Attached ADU (up to 1,000 sqft) on the same lot — 2 ADUs total per Washington HB 1337. No owner-occupancy requirement. No additional parking required. Building permit from Seattle SDCI required. Pre-approved standard DADU plans are available to speed up the permit process.
What changed in Seattle's ADU rules because of Washington HB 1337?
Washington HB 1337 (effective July 2023) codified what Seattle had already done in 2019: allows 2 ADUs per single-family lot, removes owner-occupancy requirements, and eliminates parking mandates near transit. Seattle was a national leader in ADU reform before HB 1337. The state law now ensures that other Washington cities must follow Seattle's example. Seattle's existing ADU ordinance continues to govern locally.
Do I need a permit for a home business in Seattle?
No city-issued permit is required to operate a qualifying home occupation in Seattle. You may work from home as long as you have no client visits, no non-resident employees working on-site, no external evidence of the business, and your business use is incidental to the residential use. You will need a Seattle business license and a Washington State business license regardless. Cottage food operations (baked goods, jams, etc.) require Washington Dept of Agriculture registration.
Can I do short-term rentals on Airbnb in Seattle?
Yes, with a Short-Term Rental Operator's License (approximately $75/year). If you live on-site (operator-occupied), you may rent your home for an unlimited number of nights annually. Airbnb automatically collects and remits Seattle and Washington lodging taxes (combined approximately 15.6%). Display your license number on your listing. Operating without a license carries fines of $500+ per violation.
What are the setbacks in Seattle's SF 5000 zone?
In Seattle's SF 5000 zone (most common single-family zone), the front setback is 20 feet, side setbacks are 5 feet on each side, and the rear setback is typically 25 feet (20% of lot depth, minimum 20 ft, maximum 25 ft). Maximum lot coverage is 35% (plus additional allowance for DADUs). Maximum building height is 30 feet. Verify your specific parcel using SDCI's parcel data tool — shoreline, environmental overlay, or historic designation may add requirements.
Is solar required on new homes in Seattle?
No. Washington does not have a statewide new-construction solar mandate. Seattle encourages solar through streamlined permitting and incentive programs, but it is not required. Seattle City Light offers net metering and the federal Investment Tax Credit (ITC) reduces solar installation cost by 30%. Standard residential solar permits are processed quickly through SDCI.
How do I look up the zoning for my Seattle property?
Use SDCI's Parcel Information tool at seattle.gov/sdci/permits/do-i-need-a-permit/parcel-information. Enter your address to find your zoning designation, ADU eligibility, lot size, and any overlays (environmental critical areas, shoreline, landmark, flood zone). You can also view Seattle's interactive zoning map at https://www.seattle.gov/opcd/ongoing-initiatives/seattle-2035.
Source: Seattle Building Code — Shed / Storage Building Requirements. Last verified April 5, 2026. View source