Sammamish, WA Accessory Structures: Shed & Carport Rules (2026)
Shed permit rules in Sammamish, 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
- Up to 200 sq ft floor area
- Permit-exempt height
- Up to 12 ft, grade plane to roof peak
- Excludes
- Vehicle storage buildings
- Critical areas
- Exemption void in critical areas/shoreline setbacks
- Oversized sheds
- Need a building permit under SMC 16.20.195
- Permit term
- 2 years from issuance, one 1-year extension
Summary
Sammamish lets homeowners skip a building permit for a small tool or storage shed under SMC 16.20.200(2)(a): tool sheds, storage sheds, playhouses and tree-supported play structures qualify as long as the floor area stays at or under 200 square feet and the height stays at or under 12 feet. Anything bigger, or built inside a critical area or shoreline setback, needs a full building permit.
IRC accessory structures used as tool and storage sheds, one-story tree-supported play structures, playhouses and similar uses, but not including vehicle storage, provided the floor area does not exceed 200 square feet and, except one-story tree-supported play structures, the height does not exceed 12 feet from the grade plane to the highest point of the roof.
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance O2026-598, and legislation passed through August 18, 2026).
Full Breakdown
200 lists work exempt from a building permit, and subsection (2)(a) covers IRC accessory structures used as tool and storage sheds, one-story tree-supported play structures, playhouses and similar uses, but specifically excludes vehicle storage. The floor area cap is 200 square feet, and except for tree-supported play structures the height cannot exceed 12 feet measured from the grade plane to the highest point of the roof. 200 makes clear that permit exemptions for work outside the footprint of an existing legally established structure do not apply within critical areas or within standard shoreline setbacks, both common constraints on Plateau lots near wetlands or steep slopes. 195, which requires the owner or an authorized agent to apply to the permit center and obtain a building permit before construction. 237.
Violations & Fines
Building an oversized shed, or any shed inside a critical area or shoreline setback, without first obtaining a building permit triggers SMC 16.20.355: the City can issue a stop work order and charge a special investigation fee on top of the permit fee, and may require a licensed design professional's structural certification before the work can be legalized. Continued work after a stop work order brings civil penalties under Chapter 23.100 SMC.
Frequently Asked Questions
Can I build a shed in Sammamish without a permit?
What if my shed is bigger than 200 square feet?
What happens if I build a shed without a permit when one is required?
Sources & Official References
Other rules in Sammamish
How Sammamish compares: Shed Permit Requirements by City·Compare Sammamish to another location·View the Washington accessory structures overview
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