Attached ADU (AADU) Permits in City of Tacoma

An ADU built inside or attached to the primary residence — basement conversion, garage conversion, or bump-out addition. Lower cost; constrained by the primary footprint. Junior ADUs (JADUs, ≤500 sf) are a subset of this category.

Drops the placement canvas on your parcel for attached adu (aadu) scope. Live setback + coverage + easement checks; packet generation when you’re ready.

Permit fees in City of Tacoma

Fee schedule not yet aggregated — check the City of Tacoma fee schedule directly.

City of Tacoma fee schedule

Apply via https://aca-prod.accela.com/tacoma/Default.aspx (Accela ACA portal) or in person at 747 Market Street, 3rd Floor.

Review timeline

Typical: 2160 business days

AADU-specific requirements

  • Egress on every bedroom — IRC R310 net clear opening ≥5.7 sf; sill ≤44″ from floor.
  • Smoke + CO alarms — interconnected throughout primary + AADU per IRC R314/R315.
  • 1-hr separation — required between AADU and primary in some cases; otherwise a continuous draft stop.
  • Independent kitchen + bath — full plumbing + cooking provision in the AADU.
  • Separate address / unit number — required by USPS + 911 dispatch.