Sheds
What Is It?
A shed is a small, single-story building used to store tools or other items.
What Permits Do You Need?
You don't need a permit to build a shed if it meets all of these criteria:
- The total area (or “footprint”) of the shed’s roof is 120 square feet or less
- The shed is a single-story building
- The shed sits on a simple concrete slab, pier blocks, or soil
- The shed is not attached to a house or other building
- The shed is not in or near an environmentally critical area (ECA), for example a steep slope, wetland, or flood-prone area
- The shed is only used for storage, growing plants, or similar, generally unoccupied uses
All other sheds require a permit; most require only a subject-to-field-inspection permit. You need a construction addition / alteration permit if:
- Your shed is in or near an ECA
- Your shed is larger than 750 square feet
- Your shed has beams that span more than 14 feet
You may need to apply for electrical service changes or new services from Seattle City Light.
Research the Code
Whether or not you need a permit, you must meet all code requirements when building your shed, including the building, land use, stormwater, grading, and environmentally critical areas codes.
Our Seattle Municipal Code (SMC) limits the size and location of your shed. The shed cannot be more than 12 feet tall. The combined footprint of all structures (including your house, garage, shed, and decks 36 inches or more above the ground) can’t exceed a certain percentage of your lot size. That percentage varies by zoning. For neighborhood residentialzones (NR1, NR2 and NR3), the total coverage is limited to 35 percent of the lot (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). For the residential small lot zone (RSL), the maximum lot coverage is 50 percent of the lot. For the residential small lot zone (RSL), the maximum lot coverage is 50 percent of the lot.
You usually can’t put the shed within 20 feet of the front property line or within five feet of the side property lines in neighborhood residential zones (NR1, NR2 and NR3). In the residential small lot zone (RSL), you cannot put the shed within 10 feet of the front property line, with 5 feet of the side property lines. You can put the shed in your backyard (the rear 25 feet or the rear 20 percent of the lot depth, whichever is less), ) in NR1, NR2 or NR3 zones, or within 10 feet of the rear property line (but could be up to the property line abutting the alley for RSL zones). There are also limits on the shed size and height. Read the Land Use Code for the complete requirements, submit an online question, or contact our Applicant Services Center for land use coaching for more information.
- Tip 220, Lot Coverage, Height and Yard Standards for Homes in Neighborhood Residential Zones
- Tip 221, Single Family Side Yard Easements and Accessory Structure Agreements
Should You Hire a Professional?
Shed drawings rarely require a professional stamp indicating the shed was designed by an architect or engineer. Anyone with drafting skills may prepare the drawings or you may hire a professional to help you. If you plan to build a shed in or near an ECA, you need to follow specific rules for that ECA. You may want the help of a professional to prepare documents for your application and construction permit.