City of Seattle building permits: fees, timelines & requirements (2026)
Every fee, threshold, and review window for City of Seattle permits — cited to the city's own page and re-verified weekly. Covers ADU, addition, kitchen, bathroom, basement, deck, fence, siding, windows, flooring, roofing, HVAC, electrical, plumbing, and ancillary permits (King County).
14 of 22 project types have authoritative rules on file · 10 typically require a permit · 4 often do not.
Permit department
Seattle Department of Construction & Inspections (SDCI)
Adopted code cycles
2021 IRC w/ WA amendments · 2021 WSEC
Resources
Construction permits
| Project | Permit? | Threshold | Fee | Review days | Source |
|---|---|---|---|---|---|
| Kitchen remodel | Yes | Cosmetic-only refresh exempt. Most full kitchen remodels touch electrical (new circuits for dishwasher/disposal/microwave) and plumbing (sink/dishwasher), so plan on Construction Permit (Subject-to-Field-Inspection if no structural change) plus electrical, plumbing, mechanical permits. | Subject-to-Field-Inspection if no structural change. See 2026 SDCI Fee Subtitle. | — | Cite verified 2026-04-26 |
| Bathroom remodel | Yes | Like-for-like fixture replacement in same location with no plumbing rerouting and no new circuits is sometimes exempt; any relocation, new fixture, or circuit change triggers permits. | Subject-to-Field-Inspection typical. Plus electrical, plumbing, mechanical permits. | — | Cite verified 2026-04-26 |
| Basement finish | Yes | Adding habitable rooms requires Construction Permit. Egress window required for any sleeping room (2021 IRC R310). Ceiling-height minimums and emergency-escape openings are common rejection reasons. | Construction Permit (Addition/Alteration). Plan-review fee scales with valuation. See SDCI 2026 Fee Estimator. | — | Cite verified 2026-04-26 |
| Deck | Yes | Permit required if: deck >18in above grade, OR roof deck, OR in an ECA. Decks ≤18in above grade and outside ECAs are exempt. If deck >36in above grade, it counts toward lot coverage. If deck >8ft tall, has long beams, is a roof deck, or in an ECA → Construction Permit (Addition/Alteration); otherwise Subject-to-Field-Inspection. | Subject-to-Field-Inspection permits pay 40% of plan-review fee from SDCI Fee Estimator. See 2026 Fee Subtitle. | — | Cite verified 2026-04-26 |
| Fence | Often no | No permit required if ALL of: ≤8ft tall, no masonry/concrete >6ft, not in a flood zone, not in/near an ECA. NR zones: 6ft standard, up to +2ft architectural features. Sloping sites: max 8ft if avg height between posts is 6ft. | Construction Subject-to-Field-Inspection permit when required. See 2026 SDCI Fee Subtitle. | — | Cite verified 2026-04-26 |
| Siding | Often no | Like-for-like siding replacement is treated as ordinary repair and typically exempt under 2021 IRC R105.2. Adding continuous insulation, changing the WRB system, or any modification that affects WSEC compliance triggers a Subject-to-Field-Inspection permit. | Often exempt. If permit required, Subject-to-Field-Inspection. | — | Cite verified 2026-04-26 |
| Window replacement | Often no | Like-for-like replacement in existing rough opening with U-factor compliance: typically exempt. New opening, enlarged opening, change in egress compliance, or any structural header change requires Subject-to-Field-Inspection permit. | Like-for-like usually no permit. Structural changes scale with valuation. | — | Cite verified 2026-04-26 |
| Flooring | Often no | Surface flooring exempt under 2021 IRC R105.2. Subfloor structural modification, joist alterations, or radiant heat install requires permit (mechanical/electrical for radiant). | No permit fee for surface flooring. | — | Cite verified 2026-04-26 |
| ADU / DADU | Yes | Max 2 ADUs per property (Seattle code). Pre-approved DADU plans via ADUniverse cut review to 2-6 weeks. Custom designs follow standard plan submittal (SDCI Tips 103 + 106). Owner-occupancy covenant currently required. | Construction Permit (Addition/Alteration). Pay 75% of plan-review + permit fees at application acceptance. See 2026 Fee Estimator + Director's Rule 5-2025. Pre-approved DADU plans waive most plan-review fees. | 14–84 days | Cite verified 2026-04-26 |
| Roofing | Yes | Seattle requires re-roof permit for residential (R-3) — even straight tear-off + replace. Some structural-decking-only or repair work may be exempt under SDCI client assistance memo. | Re-Roof Permit — flat fee. See 2026 SDCI Fee Subtitle. | — | Cite verified 2026-04-26 |
| HVAC | Yes | SDCI requires Mechanical Permit for any equipment install or replacement. WSEC R403 requires Manual J/S/D sizing on new systems. | Mechanical permit + electrical (if new circuit) + plumbing (if condensate to drain). | — | Cite verified 2026-04-26 |
| Electrical | Yes | WAC 296-46B requires electrical permit for ALL electrical work in residential. WA L&I issues electrical permits in Seattle (city does NOT do its own electrical inspection — L&I does). | L&I permit fees by circuit count + service size. Standard residential ~$60-$200. | — | Cite verified 2026-04-26 |
| Plumbing | Yes | WAC 51-56 requires plumbing permit for installation, replacement, or relocation. Like-for-like faucet replacement exempt. Seattle sewer side-sewer permits issued separately by SPU. | Plumbing permit fees by fixture count. Standard residential ~$80-$250. | — | Cite verified 2026-04-26 |
| Addition | Yes | Any additional floor area requires Construction Permit (Addition or Alteration). Plan review required. ECA + lot coverage + setback compliance verified at intake. | Construction Permit (Addition/Alteration). Pay 75% of plan-review + permit fees at application acceptance. See SDCI 2026 Fee Estimator. | — | Cite verified 2026-04-26 |
How this page is built
Each row is the most-recently-verified authoritative rule on file for City of Seattle and the listed project type. “Pending verification” means we have City of Seattle in our database but haven't yet personally checked the city page for that project — those rows fall back to King-County or Washington-state baselines until verified.
See the data-quality leaderboard for how we keep these current, or run an address-specific lookup on the main permits page.