Shed Permit in Seattle, WA
Permit Summary
Do You Need a Shed Permit?
Exemptions
A construction permit is not required only when all of SDCI's shed-exemption conditions are met: the detached shed is one story, its projected roof area is 120 square feet or less, it is supported on a simple slab-on-grade, pier blocks, or soil, it is not attached to another building, it is not in or near an environmentally critical area, and it is used only for storage, growing plants, or similar generally unoccupied purposes. The exemption does not waive other applicable code requirements.
Attached Shed Rules
An attached shed does not qualify for Seattle's no-construction-permit shed exemption. SDCI states that sheds not meeting all exemption conditions require a construction permit; most qualify for the Subject-to-Field-Inspection path unless regular review is triggered.
Shed Use Rules
The construction-permit exemption is limited to storage, growing plants, or similar generally unoccupied uses. A shed intended for occupied or habitable use does not fit the permit-exempt storage-shed pathway and must be reviewed under the applicable use and construction requirements.
Zoning & Placement Rules
Zoning Rules
Every shed must comply with Seattle land-use rules even when no construction permit is required. In Neighborhood Residential zones, current 2026 standards in SMC Chapter 23.44 govern lot coverage, setbacks, height, and accessory-structure placement. Permitted sheds are reviewed for Land Use Code compliance as part of SDCI review, and site-specific conditions can trigger additional land-use review.
Setback Rules
Under current Neighborhood Residential standards, the front setback is generally 15 feet on lots with one or two dwelling units and 10 feet on lots with three or more dwelling units. Where the rear lot line does not abut an alley, the rear setback is generally 15 feet for lots with one or two dwelling units and 10 feet for lots with three or more; certain other structures on lots under 5,000 square feet within a frequent-transit service area use a 5-foot rear setback, while no rear setback is required where the rear lot line abuts an alley. Side setbacks are generally 5 feet average with a 3-foot minimum, or 3 feet on qualifying lots under 5,000 square feet within a frequent-transit service area. Accessory-structure provisions can allow placement in required rear or side setbacks subject to additional conditions.
Maximum Height Rules
SDCI's current shed guidance states that a shed cannot be more than 12 feet tall. Other zone- or site-specific development standards may also apply.
Lot Coverage Rules
In current Neighborhood Residential zones, structures are generally limited to 50% lot coverage. Up to 60% coverage is allowed only for specified qualifying development, including certain frequent-transit common-amenity projects and stacked dwelling-unit development. A shed must be included in the applicable structure/lot-coverage calculation, and site-specific constraints can further limit development.
Special Area Rules
A shed in or near an environmentally critical area does not qualify for the small-shed construction-permit exemption and requires the Addition or Alteration permit path. Environmentally critical area, shoreline, steep-slope, wetland, and similar site conditions can trigger additional pre-application review, site visits, surveys, geotechnical documentation, or development restrictions.
Construction Requirements
Foundation Rules
For the shed construction-permit exemption, SDCI allows a simple concrete slab-on-grade, pier blocks, or direct support on soil. The Seattle Building Code exemption does not apply when the shed is placed on a concrete foundation other than a slab-on-grade.
Fire Separation Rules
Permit-exempt detached tool or storage sheds that qualify under Seattle Residential Code R105.2 are exempt from location-based exterior-wall protection, but projections may not extend across a lot line. For permitted residential-code sheds, SRC R302.1 fire-separation rules apply; unprotected exterior walls generally require at least 5 feet of fire-separation distance, with fire-resistance, projection, and opening limits applying at shorter distances.
Permit & Review Path
Permit / Review Path
No construction permit is required only when every small-shed exemption condition is met. Otherwise, SDCI states that most sheds can use the Construction Permit - Subject-to-Field-Inspection process. A Construction Permit - Addition or Alteration is required when the shed is in or near an environmentally critical area, is larger than 750 square feet, or has beams spanning more than 14 feet.
Trade Permits & Professional Design
Trade Permit Rules
Separate trade permits depend on the shed's installed systems. New or altered electrical wiring or equipment generally requires an SDCI electrical permit, and new electrical service or service changes may also require coordination with Seattle City Light. Other trade permits apply when the project includes work regulated under those permit programs.
Professional Design Rules
SDCI states that shed drawings rarely require a professional stamp and that anyone with drafting skills may prepare typical shed plans. A licensed architect or engineer may be required when the project falls outside applicable design-professional exceptions or when SDCI requires engineered construction documents; environmentally critical area conditions can also require specialist reports.
What You Need Before Applying
Requirements
Confirm the site's zoning and environmentally critical area conditions. If a construction permit is required, submit the Building & Land Use Pre-Application through the Seattle Services Portal with the required site and construction information. All sheds, including permit-exempt sheds, must comply with applicable building, land-use, stormwater, grading, and environmentally critical area rules, and separate trade approvals may apply to installed systems.
Required Documents
For a permitted shed, SDCI's construction-permit process generally requires a Building & Land Use Pre-Application, site plan, complete legal description, and scaled plans showing existing conditions and the proposed work. Site-specific or environmentally critical area projects may require additional documentation such as a topographic survey or geotechnical report.