Puyallup, WA Accessory Structures: Garage Conversions (2026)

A detached garage is one of the structures Puyallup Municipal Code (PMC) § 20.20.010(11)(j) expressly names as convertible into an accessory dwelling unit: an ADU may be created through internal conversion of part of the principal home or by converting an existing structure, including but not limited to a detached garage, with a cross-reference to PMC § 20.65.030(3) for garages that do not already meet current zoning. If the converted space does not get its own fire wall and separate exterior entrance, it counts only as an addition to the main house, not a legal ADU, which matters for permitting and for the parking and setback rules that attach specifically to ADUs.

PMC § 20.65.030(3), the nonconforming-structures chapter, gives a garage that already encroaches on a required setback or exceeds lot coverage limits a path to legal conversion: a nonconforming accessory structure in a residential zone may be converted into an ADU even though it does not meet current dimensional standards, provided the resulting unit otherwise satisfies the size, bedroom and quantity standards of PMC § 20.20.010(11). A converted garage still must meet the 1,000-square-foot and three-bedroom ADU caps, and if the conversion leaves less than 10 feet of separation from the principal dwelling, PMC § 20.20.010(11)(g)(i)(C) requires the unit to be fire-rated to building code standards. An ADU created this way may later be sold as a condominium unit or through a unit-lot subdivision. Converting a garage without permits, or exceeding these size and separation limits, is enforced as a Title 20 zoning violation.