Tacoma, WA Accessory Structures: ADU Permits (2026)

TMC 13.06.150 governs ADU standards. Following HB 1337 (effective June 2024 for compliance), Tacoma allows up to two ADUs per residential lot in single-family and multi-family zones — typically one attached and one detached, or two detached. The Home In Tacoma zoning package (effective February 1, 2025) further expanded allowed locations and middle-housing types. Applications go through Planning and Development Services at 747 Market Street, Room 345, and use the city's online ePlans portal. Required submittals: scaled site plan with setbacks, building elevations, floor plans, Washington State Energy Code (WSEC) compliance forms, structural plans for permanent foundations, and Tacoma Public Utilities (TPU) sewer/water capacity confirmation. Per RCW 36.70A.681, Tacoma may not impose owner-occupancy requirements, may not require off-street parking for ADUs within a half-mile of frequent transit, and must allow a maximum gross floor area of at least 1,000 square feet. DADU setbacks under TMC 13.06.150 are 5 feet sides (8 feet if a main entrance faces a side line) and 15 feet rear (0 feet from an alley). Maximum DADU height is 24 feet. Decisions are required within 60 days of a complete application under RCW 36.70B.080.