ADU Pass
Tacoma
Pierce County portion
Also in: No County
ADU Pass helps homeowners in Tacoma, Pierce County, Washington navigate the permit paperwork for building an accessory dwelling unit. This area covers 16 ZIP codes.
Map
ADU details
ADU legality: allowed
Washington preempts most local ADU restrictions. Tacoma permits ADUs by right in single-family zones per its zoning ordinance.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 150 | $2,900 | $71,250 | $74,150 |
| 600 | 600 | $2,900 | $285,000 | $287,900 |
| midpoint | 675 | $2,900 | $320,625 | $323,525 |
| maximum | 1,200 | $2,900 | $570,000 | $572,900 |
Fee breakdown (as of 2026-04)
Permitting process
- TMC 13.06 zoning verification and tip-sheet review (~3d)
Confirm parcel zoning (R-1, R-2, R-3, R-4-L, R-4, R-5, HMR-SRD, NCX, CCX, UCX, RCX) allows ADU. Review L-150 ADU Tip Sheet and DADU Coaching Tip Sheet. Verify Foss Waterway shoreline overlay or JBLM AICUZ does not apply. - Optional: select pre-approved DADU plan or schedule DADU coaching session (~14d)
Choose from Tacoma's pre-approved DADU plan catalog (free, architect-stamped, plan-check abbreviated) or schedule a DADU Coaching pre-application session with Planning & Development Services for custom designs. - Complete submittal checklists (~2d)
Fill out Submittal Checklist - Detached ADU (BLDRN) or Attached ADU (BLDRA), Residential Permit Submittal Checklist, Owner's Authorization Form, and ADU Water/Power Considerations sheet (TPU Tacoma Public Utilities). - Online submittal via Tacoma Permits portal (~1d)
Submit through tacomapermits.org Application Services. Upload site plan, floor plans, elevations, structural calcs, WSEC 2021 energy compliance, electrical clearances per TPU diagram, and any required SEPA checklist for shoreline-adjacent parcels. - Intake screening and routing (~5d)
Tacoma Permits intake screens for completeness and routes concurrently to Planning, Building, Site Development (drainage), Tacoma Fire, and Tacoma Public Utilities (Water and Power Divisions). - Concurrent plan review (~30d)
Custom DADU typically receives 2 review cycles; pre-approved DADU receives 0-1. Tacoma Public Utilities reviews electrical service capacity and water meter sizing. Tacoma Fire reviews emergency access and Knox box. - Permit issuance and fee payment (~3d)
Pay permit fees, plan-review fees, system development charges (water/sewer SDCs through Tacoma Public Utilities), traffic impact fee credit, and Washington State Building Code Council surcharge. - Construction inspections via Tacoma Permits dashboard
Footing, foundation, framing, mechanical/plumbing/electrical rough, insulation, drywall, final. Schedule via tacomapermits.org dashboard or call 253-591-5030 option 3 (residential). - Certificate of occupancy (~5d)
Final inspection sign-off triggers CO; ADU eligible for occupancy and rental.
Viability (permitted uses)
- Long-term rental: yes Long-term rental of ADU explicitly permitted; Washington owner-occupancy preemption (where applicable) makes ADU eligible for full landlord-tenant treatment.
- Short-term rental: with-restrictions STR rules vary by city. Tacoma regulates STRs separately from ADU permitting; check local STR ordinance and HOA covenants.
- Office rental: with-restrictions Detached office rental requires home occupation permit or rezoning.
- Home office: yes Home occupation permitted with restrictions on signage and customer traffic.
- Studio / workshop: yes Personal artist studio is a permitted accessory use.
- Agriculture: with-restrictions Limited urban agriculture permitted in residential zones; livestock varies by district.
- Relative support: yes Family-occupancy ADU explicitly permitted in single-family zones.
Contacts
Staff: Residential Permit Line (Residential ADU intake (option 3 on main line)), Tacoma Public Utilities - New Service (Water and electrical service for ADUs), Tacoma Fire Department - Fire Prevention (Fire access and emergency vehicle review)
Utilities
- Water: Tacoma Water Utility · 21d connect · $4,500
- Sewer: Tacoma Sewer / Wastewater · 21d connect · $5,500
- Electric: Tacoma Electric Utility · 14d connect · $1,800
- Gas: Tacoma Gas Utility · 21d connect · $1,500
Property values & taxes
Construction timeline
Realistic total: best 7mo · typical 11mo · worst 17mo
Financing
State ADU loans:
Insurance impact
HOA prevalence & preemption
Washington enacted HOA preemption of ADU bans in Substitute House Bill 1337 (2023), which amended the Washington Uniform Common Interest Ownership Act and the Washington Horizontal Property Regimes Act to prohibit common-interest communities from banning ADUs on lots in GMA-planning jurisdictions. A homeowners' association may impose reasonable aesthetic or architectural standards, but may not categorically prohibit ADUs.
Regulatory overlays (1)
- airport-noise-zone
Airport noise contours affect some parcels and may require sound-attenuation construction.
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Amendment
- Amendment
Legal history (timeline)
Current ordinance: Tacoma Municipal Code Title 13.06 (Zoning) - Accessory Dwelling Units, with L-150 ADU tip sheet, adopted 2019-03-19, last amended 2025-01-15
- 2019-03-19 — Tacoma Accessory Dwelling Unit Ordinance No. 28576 (city-ordinance)
Comprehensive overhaul of TMC 13.06 ADU provisions allowing ADUs citywide in residential zones, removing parking minimums, and creating expedited DADU pathway.
Effect: Permitted detached ADUs in all R-zones, capped DADU at 1,000 sqft (750 sqft on small lots), set 18 ft height with bonus to 20 ft for parking integration, and removed parking requirements citywide. - 2021-12-07 — Home In Tacoma Project - Near-term Code Changes (city-ordinance)
Affordable Housing Action Strategy near-term code amendments expanding two-ADU-per-lot allowance and refining building-form transitions.
Effect: Allowed two ADUs per lot in residential zones (one attached + one detached, or two attached) ahead of state mandate; added L-150 ADU coaching tip sheet program. - 2023-05-08 — Washington EHB 1337 statewide ADU enabling act (state-law)
Statewide preemption requiring two ADUs per lot, no owner-occupancy, no parking minimum within 1/2 mile of major transit, and 1,000 sqft minimum size allowance for cities >= 2,500 population.
Effect: Tacoma's 2019 and 2021 reforms already met or exceeded the EHB 1337 floor; minor compliance edits adopted in 2024 to align height-measurement language. - 2025-01-15 — Tacoma UR3 Tip Sheet update and AHAS implementation (city-ordinance)
Updated Urban Residential 3 (UR3) tip sheet incorporating middle-housing transitions and refined ADU compatibility standards.
Effect: Provided clearer guidance on combining ADUs with HB 1110 middle-housing types (duplex/triplex/fourplex) on the same lot.
Pierce County — county ADU rules and overlays
County permitting (unincorporated parcels)
Pierce County handles unincorporated permitting under its planning/development department.
Washington state — ADU law and programs
State ADU law
Washington preempts local ADU regulation in urban growth areas of cities and counties subject to the Growth Management Act through Engrossed Second Substitute House Bill 1337 (2023), codified principally at RCW 36.70A.680-.681. Cities and counties planning under the GMA must allow at least two ADUs per lot in urban growth areas, must not require owner-occupancy, must not impose minimum-lot-size or setback rules stricter than those for the primary residence, and must allow ADUs to be sold separately as condominiums. Related House Bill 1110 (2023), codified at RCW 36.70A.635, requires 'middle housing' (duplexes, triplexes, fourplexes) in most residential zones of large cities.
- RCW 36.70A.680 — Accessory dwelling units — Requirements for cities and counties planning under this chapter — Sets the minimum entitlement floor for ADUs in GMA-planning jurisdictions: at least two ADUs per lot in urban growth areas, no owner-occupancy requirement, no stricter setback or lot-coverage rules than for the primary residence, no parking requirements within a half-mile of major transit stops, and no prohibition on selling an ADU separately as a condominium.
- RCW 36.70A.681 — Accessory dwelling units — Design, size, and aesthetic standards — Caps what local governments may require in ADU design and size standards. Maximum ADU size must be at least 1,000 square feet in most zones. Street-facing facades and aesthetic review may not be used to categorically prohibit ADUs.
- RCW 36.70A.696 — Accessory dwelling units — Definitions — Statutory definitions of 'accessory dwelling unit,' 'attached accessory dwelling unit,' 'detached accessory dwelling unit,' 'owner,' and 'urban growth area' used by RCW 36.70A.680-.681.
- RCW 36.70A.635 — Middle housing — Cities planning under this chapter — HB 1110 (2023). Requires cities over specified population thresholds to allow duplexes, triplexes, fourplexes, townhouses, cottage housing, and stacked flats in most residential zones. Interacts with ADU law because ADUs and middle housing both contribute to the state's response to the GMA's housing element.
State HOA preemption
Washington enacted HOA preemption of ADU bans in Substitute House Bill 1337 (2023), which amended the Washington Uniform Common Interest Ownership Act and the Washington Horizontal Property Regimes Act to prohibit common-interest communities from banning ADUs on lots in GMA-planning jurisdictions. A homeowners' association may impose reasonable aesthetic or architectural standards, but may not categorically prohibit ADUs.
- RCW 64.38.057 — Homeowners' associations — Accessory dwelling units — Prohibits a homeowners' association governing a plat within a GMA-planning city or county from recording or enforcing a provision that prohibits the construction, use, or rental of an accessory dwelling unit on a lot. Reasonable design guidelines consistent with RCW 36.70A.681 remain enforceable.
State financing programs
The Washington State Housing Finance Commission (WSHFC) administers state-level housing finance programs. Washington does not currently operate an ADU-specific statewide grant or forgivable-loan program comparable to California's CalHFA ADU Grant, but several state programs can be used for ADU construction when program criteria are met.
State housing programs
Washington supports ADU implementation through Department of Commerce technical assistance and grant programs rather than through a single statewide pre-approved-plan catalog. The state provides model ADU code under the GMA, distributes GMA update grants to help jurisdictions comply with RCW 36.70A.680-.681, and has produced ADU guidance documents for local governments.
Federal (United States) — ADU-relevant rules and programs
Federal ADU law
The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.
Federal financing programs
Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.
Federal tax credits
There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.
Federal housing programs
HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.
ZIP Codes
- 98402
- 98403
- 98404
- 98405
- 98406
- 98407
- 98408
- 98409
- 98418
- 98443
- 98444
- 98445
- 98446
- 98465
- 98466
- 98467
Post Office
- 1102 A St, 98402
- 320 Garfield St S, 98444
- 3705 S G St, 98418
- 3801 N 27th St, 98407
- 3825 S Warner St, 98409
- 6817 27th St W, 98466