See also: House Additions & RemodelsAccessory Dwelling Unit (Mother-in-Law Apartment)

What Is It?

A brown man with short, brown hair and a beard thinking about a car in a garage.A single-family garage is used to park a car and store items; it may be in a building separate from a house or it may be attached to a house.

What Permits Do You Need?

Construction permit - subject-to-field-inspection. Most new and remodeled garages require only a subject-to-field-inspection permit. To qualify, your garage needs to be 750 square feet or less, a single story without a roof deck, and with beams spanning 14 feet or less. 

Construction permit - addition or alteration. If your project doesn’t quality for a subject-to-field-inspection permit, you will need an addition or alteration permit. If your garage will be located in an environmentally critical area (such as a steep slope or flood-prone area) or if you need to dig an area over 750 square feet for your garage’s construction (including any driveway or other paved area), you need to schedule a pre-application site visit and we may have additional requirements.

Electrical or plumbing permit. You may also need to get an electrical permit or plumbing permit if your garage will be wired for electricity or have a sink. You may also need to apply for electrical service changes or new services from Seattle City Light.

Research the code

Our Seattle Municipal Code (SMC) and Environmentally Critical Area Code limit the size and placement of your garage.

The combined footprint of your structures (including new garage), covered areas, and decks 36 inches or more above the ground can’t exceed a certain percentage of your lot size. That percentage depends upon your property’s land use zone.

In neighborhood residential zones, we limit the total coverage of all structures to 35 percent of the lot area (on lots 5,000 square feet or larger) or 1,000 square feet plus 15 percent of the lot area (on lots smaller than 5,000 square feet), and is limited to 50 percent on lots zoned as Neighborhood Residential Small Lot (RSL).

You usually can’t put a garage within the front 20 feet or the side 5 feet of your property. You may place your garage in your rear yard (within the last 25 feet or the rear 20 percent of your lot’s depth, whichever is less), but we limit its size and height.

If your garage will be located in an environmentally critical area, additional restrictions will apply. Please contact the Applicant Services Center for coaching.

Your garage will also need to meet our building code requirements. For subject-to-field-inspection permits, we check those requirements when we inspect your project during construction. For addition or alteration permits, we check them during our review of your construction plans.

Should You Hire a Professional?

Garage drawings rarely require a professional stamp from an architect or engineer. Anyone with drafting skills may prepare the drawings, or you may hire a professional to help you.

Construction and Inspections

Nathan Torgelson, Director
Address: 700 5th Ave, Suite 2000, Seattle, WA, 98104
Mailing Address: P.O. Box 34019, Seattle, WA, 98124-4019
Phone: (206) 684-8600
Phone Alt: Violation Complaint Line: (206) 615-0808
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SDCI issues land use, construction, and trade permits, conducts construction and housing-related inspections, ensures compliance with our codes, and regulates rental rules. SDCI is committed to an antiracist workplace and to addressing racism through our work in the community.