Accessory Structures in Auburn, WA (2026)
5 verified accessory structures rules for Auburn, Washington, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Auburn permits ADUs and DADUs under ACC 18.31.120 per WA HB 1337. Up to two ADUs per lot, max 1,000 sq ft, no owner-occupancy rule. Unit lot subdivision for fee-simple sale is allowed.
Auburn ADU and DADU Rules
Few RestrictionsShed Rules
Auburn follows the 2021 IRC through ACC 15.36. Sheds 200 sq ft or less and 10 ft or less tall do not need a building permit but must meet ACC 18.31 setbacks: 5 ft rear-side, 10-15 ft front. Larger sheds require permits.
Auburn Shed Size and Permit Rules
Few RestrictionsGarage Conversions
Converting a garage to living space in Auburn requires a building permit under ACC 15.36. Independent units become ADUs. Replacement parking not required under WA HB 1337 near transit.
Auburn Garage Conversion Rules
Some RestrictionsCarport Rules
Carports in Auburn follow ACC 15.36 and 18.31. Open carports under 200 sq ft may be permit-exempt but must meet setbacks. Attached carports always require a building permit regardless of size.
Auburn Carport Permit Rules
Few RestrictionsTiny Homes
Auburn allows tiny homes on foundations as dwellings or ADUs if they meet WA Building Code IRC Appendix Q. Tiny homes on wheels are RVs and cannot be permanent dwellings except in approved RV parks.
Auburn Tiny Home Rules
Some RestrictionsLooking for King County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Auburn city rules.
Accessory Structures in King County →