Do I Need a Permit to Build a Shed in Seattle, WA?

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Project type City Shed size (sq ft) Stories Electrical work planned? Plumbing planned?

Fees

Estimated city fees

Baseline for a simple permitted deck: $200–$500 estimated SDCI fees for an STFI-permitted shed (121–750 sq ft); sheds ≤ 120 sq ft meeting exemption criteria require no building permit fee

Fee	Amount	Notes
STFI permit (sheds 121–750 sq ft)	$200–$500 (estimated range)	STFI permits pay 40% of the calculated plan review fee — a significant discount over full Construction permits. Fees are project-value-based. All fees are due at permit issuance. SDCI base hourly rate is $292/hour (2026). Use the SDCI Fee Estimator spreadsheet for a project-specific estimate.
Full Construction permit (sheds over 750 sq ft)	$500–$1,500 (estimated range)	75% of plan review and permit fees due at application acceptance; remainder due before permit issuance. Includes hourly review charges.
Electrical permit (via Seattle City Light)	$75–$200 (estimated range)	Required if the shed has any electrical wiring. Applied through Seattle City Light, not SDCI.
Plumbing sub-permit	$75–$200 (estimated range)	Required if the shed includes plumbing fixtures.
Technology surcharge	Varies	Added on top of all SDCI permit fees.

Documents

Required documents

Completed permit application through the Seattle Services Portal.
Site plan drawn to scale showing property lines, existing structures, setbacks, and the proposed shed location and dimensions.
Floor plan and elevation drawings showing shed dimensions, height, roof pitch, and materials.
Foundation plan showing slab, pier block, or soil base design.
Structural details for prefabricated shed kits: manufacturer installation instructions.
Property survey or recorded plat if the shed is near a setback line or shared property boundary.
Environmentally Critical Area (ECA) assessment if the property is flagged as in or near an ECA.
HOA approval documentation if required by subdivision CC&Rs.
Homeowner authorization if a contractor files on the owner's behalf.

Timeline

Typical timing

Plan review: 3–5 business days (STFI screening); 4–12 weeks (full Construction)
Total cycle: 1–3 weeks (STFI); 6–16 weeks (full Construction)

STFI permits are processed in days and use field inspection instead of pre-construction plan review. Full Construction permits have variable review times tracked on SDCI's Construction Permit Performance dashboard. All permits are valid for 18 months from issuance.

Process

How the permit process works

Determine whether your shed requires a permit Check your shed's roof footprint. Sheds 120 sq ft or less meeting all exemption conditions (single-story, simple foundation, detached, not in an ECA, storage use only) need no permit. Sheds 121–750 sq ft may qualify for the streamlined STFI permit. Sheds over 750 sq ft or with complex features require a full Construction permit.
Verify zoning setbacks and lot coverage All sheds must comply with SMC Title 23 setbacks. In Neighborhood Residential zones: 20 ft front, 5 ft side, and placement within the rear 25 ft or rear 20% of lot depth. Accessory structures are limited to 12 ft in height. Total lot coverage cannot exceed 35% on standard lots. Check your specific parcel with SDCI.
Check for Environmentally Critical Areas If your property is in or near an ECA (steep slopes, wetlands, streams), no exemption applies — even sheds under 120 sq ft require a full Construction permit. Use SDCI's GIS tools to check your property's ECA status before proceeding.
Prepare your site plan and drawings Draw a site plan showing the lot boundary, existing structures, setbacks, and the shed's footprint and dimensions. Prepare elevation drawings showing height, roof pitch, and materials. For STFI permits, plans are reviewed by the inspector in the field rather than through pre-construction plan review.
Submit through the Seattle Services Portal Apply for an STFI or Construction permit through the Seattle Services Portal at cosaccela.seattle.gov. Upload your plans and pay the applicable fees.
Schedule field inspection (STFI) or respond to plan review (Construction) For STFI permits, the inspector reviews building code compliance on-site during construction — this replaces pre-construction plan review. For full Construction permits, respond to any plan review comments and resubmit updated documents.
Begin construction after permit issuance Post the permit at the job site. Do not start permitted work before the permit is issued. For exempt sheds, confirm zoning compliance and ECA clearance before breaking ground.
Pass required inspections Request inspections through the Seattle Services Portal. STFI permits involve field inspections during construction. Full Construction permits require foundation, framing, and final inspections. Electrical permits are inspected separately through Seattle City Light.
Close out the permit After the final inspection passes, the permit is closed. Retain all documentation for insurance, title review, and future resale.

Code basis

What Austin reviews against

Seattle Residential Code §R105.2 and Seattle Building Code §106.2 for permit exemptions; Seattle Municipal Code Title 23 (Land Use Code) Chapters 23.44 (Neighborhood Residential) and 23.45 (Residential Small Lot) for zoning and setback standards; SMC 25.09 for Environmentally Critical Areas.

Residential permit page AB+C portal

If you skip the permit

What can go wrong

SDCI can issue a stop-work order if unpermitted construction is discovered.
Fines and penalties can accumulate until the violation is resolved through an after-the-fact permit or removal of the structure.
An after-the-fact permit may require opening completed work for inspection and costs more than the original permit.
Insurance claims involving shed damage or liability may be denied if the structure was unpermitted.
Unpermitted sheds violating zoning setbacks or lot coverage limits can complicate real estate transactions and may require removal.
Unpermitted construction in or near an Environmentally Critical Area can trigger significant environmental code violations and remediation requirements.
Unpermitted electrical work creates fire and safety hazards with no inspector verification.

FAQ

Common Austin deck permit questions

Do I need a permit to build a shed in Seattle, WA?

It depends on the size and location. Sheds with a roof footprint of 120 square feet or less are exempt if they are single-story, have a simple foundation, are detached, not in an ECA, and used only for storage. Sheds 121–750 sq ft can use the streamlined STFI permit. Sheds over 750 sq ft need a full Construction permit. All sheds must comply with zoning setbacks.

What is the maximum shed size allowed without a permit in Seattle?

Under Seattle Residential Code §R105.2, sheds with a roof footprint of 120 square feet or less are exempt from a building permit — provided they are single-story, have only a slab, pier blocks, or soil foundation, are not attached to another building, are not in an ECA, and are used only for storage or similar purposes. You still must meet SMC Title 23 zoning setbacks.

What is an STFI permit for a shed in Seattle?

A Subject-to-Field-Inspection (STFI) permit is a streamlined permit for sheds between 121 and 750 sq ft. Instead of pre-construction plan review, an inspector reviews building code compliance on-site during construction. STFI permits cost only 40% of the standard plan review fee and are processed in days rather than weeks.

What are the setback requirements for a shed in Seattle?

In Neighborhood Residential zones (NR1, NR2, NR3), accessory structures require a 20-foot front setback and 5-foot side setback, and must be placed within the rear 25 feet or rear 20% of lot depth. Height is limited to 12 feet. In Residential Small Lot (RSL) zones, the front setback is 10 feet. Verify your specific parcel with SDCI at (206) 684-8600.

Does adding electricity to my shed require a permit in Seattle?

Yes. Any electrical work requires a separate electrical permit through Seattle City Light (not SDCI). Adding electrical also disqualifies the shed from the building permit exemption, so a minimum STFI permit would be required.

How much does a shed permit cost in Seattle?

STFI permits (121–750 sq ft) typically cost $200–$500, as they pay only 40% of the calculated plan review fee. Full Construction permits (over 750 sq ft) range $500–$1,500. The SDCI base hourly rate is $292/hour (2026). Use the SDCI Fee Estimator spreadsheet for a project-specific estimate. Permit-exempt sheds (≤ 120 sq ft) incur no fee.

How long does it take to get a shed permit in Seattle?

STFI permits are processed in a few days and use field inspection instead of plan review, with total project timing of 1–3 weeks. Full Construction permits take 4–12 weeks for plan review, with total timing of 6–16 weeks. All permits are valid for 18 months from issuance.

What if my property is in an Environmentally Critical Area?

If your property is in or near an ECA (steep slopes, wetlands, streams), no permit exemption applies. Even a shed under 120 sq ft requires a full Construction permit with environmental review. Check your property's ECA status using SDCI's GIS tools before planning your shed.

Sources

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