MC2 Sheds

Building a Shed in Anacortes? Here's What You Need to Know

Skagit County

Anacortes sits on Fidalgo Island in Skagit County and is the gateway to the San Juan Islands. The city has a unique 144 square foot threshold for accessory structures — sheds at or under this size and 12 feet in height get reduced setbacks: 3 feet on interior sides and 5 feet from the rear (unless you back up to an alley). Even better, one detached accessory structure under 144 sq ft doesn't count toward your lot coverage. Here's what the Anacortes Municipal Code says.

Building Codes & Permits in Anacortes

Shed Permit RulesCity of Anacortes
Max Shed Size (No Permit)144 sq ft and under 12 ft height
Max Shed Height (Overall)12 ft for reduced setback sheds
Setbacks — Interior Side3 ft (for sheds \u2264144 sq ft / 12 ft)
Setbacks — Rear (No Alley)5 ft (for sheds \u2264144 sq ft / 12 ft)
Lot Coverage ExclusionOne shed \u2264144 sq ft excluded from lot coverage calculation

The 144 sq ft threshold is unique to Anacortes. Larger accessory structures follow zone-standard setbacks and height limits.

Structures must comply with required setbacks from property lines even if exempt from a building permit.

From the Municipal Code

“Interior side setbacks: Three feet for accessory structures no larger than 144 square feet and 12 feet in height. Rear setbacks not adjacent to a platted alley: Five feet for accessory structures no larger than 144 square feet and 12 feet in height.”

AMC 19.47.020 — Accessory Structure Setbacks →

“One detached accessory structure not exceeding 144 square feet is permitted without counting as part of the lot coverage.”

AMC 19.42.110 — Lot Coverage Exclusion →

What You Need to Know

  • ●144 sq ft sweet spot (AMC 19.47.020): Anacortes uses 144 sq ft (not the typical 200 sq ft) as the threshold for reduced setbacks and lot coverage exclusions. At this size and under 12 ft, you get 3 ft side setbacks and 5 ft rear setbacks.
  • ●Lot coverage bonus (AMC 19.42.110): One detached accessory structure not exceeding 144 sq ft is excluded from lot coverage calculations. This is significant on smaller island lots where coverage limits are tight.
  • ●Setbacks (AMC 19.47.020): For sheds 144 sq ft or less at 12 ft or under: 3 ft interior side setback, 5 ft rear setback (not adjacent to alley). Larger structures follow standard zone setbacks.
  • ●Island weather: Anacortes gets less rainfall than most of western Washington due to the Olympic rain shadow, but salt air and wind exposure are real factors for shed materials and finishes.
  • ●Outside city limits? If your property is in unincorporated Skagit County or on Fidalgo Island outside Anacortes city limits, Skagit County rules apply instead.
  • ●Utilities: Even if the structure is exempt, any electrical or plumbing work requires a separate trade permit.

City of Anacortes Resources

Have questions about permits or zoning? We don't have all the answers, but we deal with this stuff regularly and can usually help you figure it out. Reach out with your address and we'll point you in the right direction.

Building codes and permit requirements are subject to change. Contact your local building department to verify current regulations before beginning your project.

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