Garage conversion rules in Federal Way, WA — sometimes called garage-to-ADU or accessory living unit conversions — govern permits, ceiling height, egress, and parking replacement.
Garage conversions in Federal Way require building permits under FWRC 13.15 and 13.22. Habitable conversions trigger egress, insulation, smoke/CO, and utility permits. Conversions to ADUs are allowed under HB 1337.
Converting a garage to habitable space requires a building permit under FWRC Chapter 13.15 (Building Code) and FWRC Chapter 13.22 (Residential Code), both adopting the Washington State Building Code with local amendments. Conversions must meet: R-value insulation requirements under the Washington State Energy Code; egress window sizing in any new bedroom (WAC 51-51); smoke and CO alarm placement (WAC 51-51-0314, RCW 19.27.530); mechanical and ventilation standards; and plumbing and electrical permits when those systems are installed. The converted space must match the height, floor flatness, and fire-rated-assembly standards for habitable use. If the conversion becomes an ADU, it falls under FWRC 19.200 and 19.265 ADU rules (HB 1337) and can be up to 1,000 sq ft. If off-street parking minimums apply to your zone, eliminating the garage may require replacement parking unless the parcel is within 1/2 mile of major transit (HB 1337 parking exemption). Unpermitted conversions are commonly flagged during resale inspections and can trigger retroactive permit requirements and mitigation.
Unpermitted garage conversion: stop-work order plus civil infraction under FWRC 1.15. Retroactive permits typically require opening walls for inspection or full removal of the conversion. Habitable-space defects can create life-safety code violations.
Federal Way, WA
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Federal Way, WA
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Federal Way, WA
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Federal Way, WA
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Federal Way, WA
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Federal Way, WA
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