Accessory Structures in Lynnwood, WA (2026)
3 verified accessory structures rules for Lynnwood, Washington, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
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.
Lynnwood ADU Rules & Accessory Dwelling Unit Regulations
Some RestrictionsShed Rules
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.
Lynnwood Shed Rules & Outbuilding Regulations
Some RestrictionsGarage Conversions
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.
Lynnwood Garage Conversion Rules & Requirements
Some RestrictionsLooking for Snohomish County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Lynnwood city rules.
Accessory Structures in Snohomish County →