Whatcom County, WA Accessory Structures: Shed & Carport Rules (2026)
Shed permit rules in Whatcom County, WA, also referred to as storage shed, backyard shed, or accessory building regulations, set size limits, setbacks, and when a building permit is required.
Key Facts
- Permit-exempt size
- 200 sq ft or less, WCC 15.04.030(C)(1)
- Separation required
- 10 ft walls, 6 ft eaves
- Max wall height
- 10 feet
- Max building height
- 11 feet 6 inches
- Misdemeanor penalty
- Up to $1,000 or 90 days
- Permit validity
- 2 years, one 1-year extension
Summary
A backyard shed in unincorporated Whatcom County skips the building permit only if its footprint stays at or under 200 square feet, under WCC § 15.04.030(C)(1). Cross the size, separation, or height limits and Planning and Development Services requires a full building permit before you build.
1. One-story detached, non-habitable accessory structures without basements, used as tool and storage sheds, playhouses, and similar uses, including gazebos, trellis, pergolas and arbors; provided that: a. The building footprint does not exceed 200 square feet (18.6 sq. m) measured outside wall to outside wall; b. Accessory structures maintain a minimum separation of 10 feet [3,048 mm] between exterior walls, and a minimum separation of 6 feet [1829 mm] between eaves of adjacent buildings on the same property; c. The accessory structure meets all applicable setback requirements; d. The maximum wall height is 10 feet (3,048 mm); e. The maximum building height is 11 feet 6 inches (3,505 mm); and, f. The maximum eave overhang is 24 inches (610 mm).
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4963078; v4 updated 2026-06-23; through 06-23-2026).
Full Breakdown
The exemption covers one-story, non-habitable accessory structures such as tool sheds, playhouses, gazebos, and pergolas, but only if every condition is met: the footprint measured outside wall to outside wall is 200 square feet or less; the shed sits at least 10 feet from any other building's exterior walls and 6 feet eave to eave; the wall height tops out at 10 feet and the overall building height at 11 feet 6 inches; the eave overhang runs no more than 24 inches; and the structure still clears every property-line and critical-areas setback that applies to its zoning district.
020(C)(2)(1) caps the same kind of exempt structure at just 120 square feet with wider 20-foot wall and 16-foot eave separations, so a shed on a commercial parcel is held to a tighter standard. 030(D), accompanied by the fee set in the Unified Fee Schedule. 050, with a single one-year extension available on request.
Violations & Fines
Building a shed that exceeds the 200-square-foot exemption, or any of its separation or height limits, without first obtaining a permit is a misdemeanor under WCC § 15.04.050(D), punishable by a fine of up to $1,000, up to 90 days in jail, or both, with each day the violation continues counted as a separate offense. The county can instead pursue a civil penalty of up to $1,000 per day under WCC § 15.04.050(F); the property owner has 30 days to apply for remission or mitigation and 10 days to appeal a final decision to the county council.
Frequently Asked Questions
How big can my shed be in Whatcom County without a permit?
Does an exempt shed still need to follow setback rules?
What if my shed is bigger than 200 square feet?
Sources & Official References
Other rules in Whatcom County
How Whatcom County compares: Shed Permit Requirements by City·Compare Whatcom County to another location·View the Washington accessory structures overview
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