Before You Build in Lynnwood, WA: Permit & Rule Checklist (2026)

Fence height is regulated by LMC §21.10.100. In residential zones, fences up to 6 ft are generally allowed in side and rear yards. Fences over 3 ft are considered vision-obscuring and may not be placed within intersection sight-distance triangles (two sides of 30 ft at corners) or driveway sight-distance triangles (two sides of 15 ft). A decorative trellis or adornment may add up to 2 ft (maximum 8 ft total).

Lynnwood adopts the International Swimming Pool and Spa Code (ISPSC) by reference under Lynnwood Municipal Code 16.24.010, as amended by the Washington State Building Code Council. Residential pools and spas more than 24 inches deep require a barrier at least 48 inches high with self-closing, self-latching gates, openings that will not pass a 4-inch sphere, and maximum 4-inch ground clearance. A building permit is required.

Garage conversions to habitable space or ADUs require a building permit under WAC 51-50. Conversions must meet habitability, energy code, and zoning requirements. HB 1337 (2023) facilitates ADU conversions with reduced design and impact fee restrictions.

Washington State HB 1337 (2023) requires Lynnwood to allow up to 2 ADUs per single-family lot. Detached ADUs in Lynnwood can be up to 1,200 sq ft and 16 ft tall; above-garage ADUs may reach 18–20 ft. No owner-occupancy requirement under HB 1337 (effective for Snohomish County cities ~May 31, 2025). Building permit required.

Sheds and accessory structures in Lynnwood must comply with LMC zoning setback requirements and the Washington State Building Code (WAC 51-50). Small sheds under 200 sq ft may be exempt from a full building permit but must still meet setback requirements. Contact the building division to confirm.

Recreational fires in Lynnwood are allowed if small (under 3 ft diameter), 25 ft from structures, constantly attended, with water nearby, using dry wood only. Prohibited during any active burn ban.

Outdoor burning is prohibited in Lynnwood city limits. Under LMC §10.16.020, no fire may be built in any public park except on provided cooking grills. Debris burning, yard waste burning, and burn barrels are all prohibited. Recreational fire pits may be allowed under Puget Sound Clean Air Agency rules during permitted conditions. Illegal fire fines start at $2,000.

Tree removal in Lynnwood is regulated under the Community Development Code, including critical area provisions. Significant trees in critical areas or during development require permits. Street trees require Public Works authorization. Contact Development & Business Services for specific requirements.