Addition permits in Tacoma: fees, timeline & requirements (2026)

When does a home addition need a permit in Tacoma?

Permit required for any addition to an existing building, OR any new accessory structure ≥200 sqft. Alteration/addition <80% of building valuation = Residential Alteration (BLDRA) permit. ≥80% = Residential New Construction (BLDRN) permit (which subsumes site-development review).

How Tacoma adopted this rule

The threshold comes from the state code (WAC 51.51), which Tacoma adopts by reference in the provision quoted below.

“The International Building Code, International Residential Code, and International Existing Building Code, as adopted and amended by the Washington State Building Code Council under the State Building Code, as defined in TMC § 2.02.100, are hereby adopted as the official Building Code of the City of Tacoma. The Tacoma Building Code as defined in TMC § 2.02.100 is also amended to include the adoption of IBC Appendix Chapter G, the adoption of IEBC Appendix A, and a new Appendix J added to the IEBC.”

Source ↗verified 2026-04-29

What Tacoma says in its own permit handout

From Residential Garages and Sheds, published by Tacoma. This is the jurisdiction's own guidance on its permit process, not the ordinance text — where the two differ, the code governs.

“A building permit is required for any addition to an existing building or for any new accessory structure that is 200 square feet or larger.”

Handout ↗read 2026-09-05

Required submittals

• Site plan to scale 1"=20'
• Floor plan 1/4"=1'
• Building elevations
• Foundation plan
• Roof framing plan
• Wall sections
• Plumbing/mechanical plans

Inspection sequence

1. Foundation/footing
2. Plumbing rough-in
3. Electrical rough-in
4. Mechanical rough-in
5. Framing
6. Insulation
7. Drywall
8. Final

Contractor specialties needed

General contractor

Notes & caveats

From Tacoma residential-permit-process tip sheet: "BLDRA (Residential Alteration/Addition) — Remodels, additions, alterations of less than 80% building valuation, miscellaneous structures without living space or storage space (i.e. walls, fences, pools)." From garages-and-sheds tip sheet: "A building permit is required for any addition to an existing building or for any new accessory structure that is 200 square feet or larger." Applies to single-family + duplex + townhomes (≤6 units, ≤3 stories).

Addition permit fee estimate in Tacoma

Worked example for a $120,000 home addition project (building permit). Your actual fee scales with project valuation.

Tacoma prices a single-family or duplex addition as one combination building, mechanical and plumbing permit (PDS Fee Schedule Table 8-4): 2.81% of the ICC Building Valuation Data value of the added floor area, plan review at 45% of that fee, and a site development permit (grading and erosion control) at 65% with its plan review at 45% of the building permit fee. Table 1 adds the Technology Program (5%), Natural Resources Program (5%) and Reserve Fund (2%) on permit and plan review fees and Emergency Preparedness (5%) on permit fees; the state building code fee is $6.50. Electrical permits are separate, issued by Tacoma Power (TMC 12.06A). Computed from Tacoma's adopted fee schedule · source ↗. Land use, fire and engineering review, intake, impact and utility fees, where they apply, are charged separately.