City of Seattle building permits: fees, timelines & requirements (2026)
What needs a permit in the City of Seattle and what triggers one — each row quoted from the city's own code or permit page, with the source linked and the source page checked weekly for changes. Fees and review times appear where the city publishes them. Covers ADU, addition, kitchen, bathroom, basement, deck, fence, siding, windows, flooring, roofing, HVAC, electrical, plumbing, and ancillary permits (King County).
18 of 23 project types have authoritative rules on file · 10 always require a permit · 13 depend on the scope · 0 do not.
Get your lot in 3D with zoning, setbacks, and the exact permits your project needs — cited to the City of Seattle's source.
Permit department
Seattle Department of Construction & Inspections (SDCI)
Adopted code cycles
2021 IRC w/ WA amendments · 2021 WSEC
Resources
Construction permits
| Project | Threshold | Fee | Review days | Source |
|---|---|---|---|---|
| Kitchen remodel Depends on scope | No permit for cabinets, counters, paint or tile. A permit once you replace a sink or faucet (plumbing, from Public Health), add circuits (SDCI electrical), run gas or change walls, and an SDCI construction permit for any remodel beyond cabinets and finishes once the work on the house is worth more than $6,000 in six months. In a special flood hazard area, or on a parcel with an environmentally critical area, even the exempt work needs floodplain development approval or the Director's approval of an exemption. 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. | FeeAbout $1,277 for a $35,000 project, when a permit is needed | ReviewNot published by the city | Cite verified 2026-04-26 |
| Bathroom remodel Depends on scope | Tile, paint and finishes need no permit. Replacing any fixture or faucet, even in the same spot, needs a plumbing permit from Public Health – Seattle & King County; new circuits need an SDCI electrical permit. An SDCI construction permit is needed to move walls, and for any remodel beyond finishes once the work on the house is worth more than $6,000 in six months. In a special flood hazard area, or on a parcel with an environmentally critical area, even the exempt work needs floodplain development approval or the Director's approval of an exemption. 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. | FeeAbout $978 for a $22,000 project, when a permit is needed | ReviewNot published by the city | Cite verified 2026-04-26 |
| Basement finish Always | Finishing a basement into habitable space needs a building permit; egress and ceiling height are the usual review items. 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. | FeeAbout $1,984 for a $40,000 project | ReviewNot published by the city | Cite verified 2026-04-26 |
| Deck Depends on scope | A deck 18 in or less above grade, not over a basement or story below, outside a flood hazard area and not on an environmentally critical area parcel needs no permit, at any size and attached or not. Otherwise it needs a permit or approval. 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. | FeeAbout $884 for an $18,000 project, when a permit is needed | ReviewNot published by the city | Cite verified 2026-04-26 |
| Fence Depends on scope | No permit for a fence 8 ft or under with no masonry or concrete over 6 ft, outside a flood hazard area and off an environmentally critical area parcel. Any one of those needs a permit or approval. 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. | FeeAbout $602 for a $6,000 project, when a permit is needed | ReviewNot published by the city | Cite verified 2026-04-26 |
| Siding Depends on scope | Replacing siding needs no building permit in Seattle. Replacing sheathing, changing structure, or altering doors or windows needs one. In a special flood hazard area, or on a parcel with an environmentally critical area, even the exempt work needs floodplain development approval or the Director's approval of an exemption. Seattle Residential Code R105.2 item 10 exempts siding replacement from a building permit: "Replacement of siding. This shall not include structural changes, replacement of sheathing or alteration to doors and windows." A permit is needed when the job changes structure, replaces sheathing, or alters doors or windows. Item 10 refers insulation to Energy Code R503.1.1, Exceptions 2 and 3. | FeeAbout $884 for an $18,000 project, when a permit is needed | ReviewNot published by the city | Cite verified 2026-09-22 |
| Window replacement Depends on scope | Seattle's code has no window exemption of its own. Replacing windows needs no building permit only as minor work: all minor work on the house worth $6,000 or less in any six months, this job included, in the same openings, with nothing loadbearing changed and no smaller escape window. Over $6,000 in six months, or a new or enlarged opening, needs a permit. In a special flood hazard area, or on a parcel with an environmentally critical area, even the exempt work needs floodplain development approval or the Director's approval of an exemption. | FeeAbout $649 for an $8,000 project, when a permit is needed | ReviewNot published by the city | Cite verified 2026-10-02 |
| Flooring Depends on scope | Replacing floor surfaces needs no permit. Changing the subfloor or joists needs a building permit; radiant floor heat needs an SDCI electrical permit, except a listed heat mat set in tile grout on an existing circuit. In a special flood hazard area, or on a parcel with an environmentally critical area, even the exempt work needs floodplain development approval or the Director's approval of an exemption. Surface flooring exempt under 2021 IRC R105.2. Subfloor structural modification, joist alterations, or radiant heat install requires permit (mechanical/electrical for radiant). | FeeAbout $602 for a $6,000 project, when a permit is needed | ReviewNot published by the city | Cite verified 2026-04-26 |
| ADU / DADU Always | An ADU or DADU always needs a building permit, and usually trade permits with it. Max 2 ADUs per property. Pre-approved DADU plans via ADUniverse cut review to 2-6 weeks; custom designs follow standard plan submittal (SDCI Tips 103 + 106). Owner-occupancy is not required and cannot be — RCW 36.70A.681(1)(b) bars a city from requiring the owner to occupy the ADU or another unit on the lot, so both units may be rented. A covenant recorded under the old rule can be released; SDCI publishes the Release of Owner Occupancy Covenant for ADUs form for exactly that. | FeeAbout $5,459 for a $200,000 project | ReviewNot published by the city | Cite verified 2026-04-26 |
| Roofing Depends on scope | A roof recover or a like-for-like roof replacement needs no building permit in Seattle. Replacing any sheathing, changing the framing or pitch, or adding skylights or other changes to the building envelope needs one. In a special flood hazard area, or on a parcel with an environmentally critical area, even the exempt work needs floodplain development approval or the Director's approval of an exemption. Seattle Residential Code R105.2 lists as work exempt from a building permit: "11. Roof recover." and "12. Roof replacement if no changes are made to the building envelope other than adding or replacing insulation, and the work is equivalent to or better than the existing structure. Permits are required for structural changes and replacement of sheathing of any size." Energy Code R503.1.1, Exceptions 2 and 3, still set the insulation requirement where the roof cavity is exposed. | FeeWhere re-roofing needs an SDCI permit, a commercial re-roofing permit is half the SDCI base fee, $146. | ReviewNot published by the city | Cite verified 2026-09-16 |
| HVAC Depends on scope | Installing or replacing heating, cooling or ventilation equipment needs an SDCI mechanical permit. Replacing a component part does not, and neither do portable units that together cover 40 percent or less of the home's requirement and total 3 kW (electric) or 10,000 Btu input (fuel) or less. In a special flood hazard area, or on a parcel with an environmentally critical area, replacing a component part still needs floodplain development approval or the Director's approval of an exemption. SDCI requires Mechanical Permit for any equipment install or replacement. WSEC R403 requires Manual J/S/D sizing on new systems. | FeeWhere HVAC work needs a permit, SDCI's mechanical permit fee is $60.35 for each furnace, heat pump or wall heater and $59.85 for each appliance vent installed separately. | ReviewNot published by the city | Cite verified 2026-04-26 |
| Electrical Depends on scope | Electrical work needs an SDCI electrical permit, except like-in-kind replacement of up to five light fixtures, switches, dimmers, receptacles or lamps, branch-circuit breakers and similar controls, a household appliance on its existing circuit, or one motor of 10 hp or less; a listed heat mat set in tile grout; and communication wiring in a house. A sixth fixture or a new circuit needs one. Electrical permit required for ALL electrical work in residential. Seattle runs its own electrical program: SDCI issues AND inspects electrical permits inside city limits (NOT L&I — L&I only handles contractor licensing). Most residential work is issued over the counter, same day, online through the Seattle Services Portal; OTC eligible under 5,000 sf or under 400 A. Plan review only per Seattle Electrical Code Art. 80 §80.50/80.51. | FeeSDCI, not L&I, issues Seattle's electrical permits. | ReviewNot published by the city | Cite verified 2026-07-27 |
| Plumbing Depends on scope | In Seattle, stopping a leak or clearing a clog needs no plumbing permit. Replacing anything, even a faucet or a fixture in the same spot or a water heater, needs one, from Public Health – Seattle & King County. SDCI does NOT issue plumbing permits in Seattle — the Seattle Plumbing Code is enforced by Public Health – Seattle & King County, and plumbing permits are applied for there. Side sewer is a third authority (SPU). WAC 51-56 requires a plumbing permit for installation, replacement, or relocation; like-for-like fixture/faucet replacement in the same location is generally exempt. Separately, SDCI requires no construction permit for minor repairs or alterations costing $6,000 or less in any 6-month period — but that exemption never covers load-bearing supports, building-envelope changes, or work reducing egress, light, ventilation or fire resistance, regardless of cost. | FeePlumbing and gas piping permits in Seattle come from Public Health – Seattle & King County, not SDCI: apply and request inspections through Public Health. | ReviewNot published by the city | Cite verified 2026-07-27 |
| Addition Always | Adding floor area always needs a building permit. Any additional floor area requires Construction Permit (Addition or Alteration). Plan review required. ECA + lot coverage + setback compliance verified at intake. | FeeAbout $4,157 for a $120,000 project | ReviewNot published by the city | Cite verified 2026-04-26 |
| Solar (rooftop PV) Always | Rooftop solar needs an SDCI electrical permit. SDCI waives the building permit for a residential rooftop system that meets its Tip 420 criteria. | FeeSDCI's electrical permit for a solar system below 12 kW is $438, plus a $55.48 administrative fee, and it needs supporting documents and a one-line diagram (SMC 22.900D.150, Table D-15). | ReviewNot published by the city | Cite verified 2026-10-02 |
| Heat pump Depends on scope | Installing or replacing a heat pump needs an SDCI mechanical permit. Replacing a component part does not, and neither do portable units that together cover 40 percent or less of the home's requirement and total 3 kW (electric) or 10,000 Btu input (fuel) or less. In a special flood hazard area, or on a parcel with an environmentally critical area, replacing a component part still needs floodplain development approval or the Director's approval of an exemption. | FeeSDCI's mechanical permit fee for a heat pump is $60.35 per unit (SMC 22.900D.090, Table D-8). | ReviewNot published by the city | Cite verified 2026-10-02 |
Ancillary & non-building permits
| Project | Threshold | Fee | Review days | Source |
|---|---|---|---|---|
| Demolition Always | Demolishing a structure needs a permit; asbestos and lead notifications are separate. 2021 IBC Section 105.1 + WA-adopted IRC R105.1: demolition of any structure or portion thereof requires a permit. Tear-out of interior finishes only is generally treated as alteration. Asbestos / lead notification often required separately under WAC 173-303 / 296-62. | FeeWhere a demolition needs an SDCI permit, the fee is 1.5 times the SDCI base fee, $438, plus the 5% technology fee. | ReviewNot published by the city | Cite verified 2026-10-02 |
| Right-of-way Always | Any work in or occupation of the public right of way needs a right-of-way permit from the city, or from the agency that owns the street. Issued by city public works (or SDOT in Seattle) under local ROW ordinance. Triggered by physical occupation of or work within the public ROW including driveway aprons, curb cuts, sidewalk replacement, utility tie-ins, hauling routes, and temporary construction staging. | FeeWhere work in the street needs a Street Use permit, the Seattle Department of Transportation sets and collects its fees (SMC 15.04.074, through SMC 22.900G.020). | ReviewNot published by the city | Cite verified 2026-05-02 |
| Side sewer Always | SPU's side sewer permit is needed to connect to the City's sewer and to build, repair, alter, cap or abandon any side sewer, with no minimum length. Seattle Public Utilities (SPU) issues the side sewer permit, and inspects the work, for property served by the City's sewer and drainage system. A permit is required to connect a property to the public sewer or a storm drain, and to construct, repair, alter or add to, or to abandon, remove or cap, any sanitary or drainage side sewer (SMC 21.16.070). There is no minimum length: SPU requires its repair permit anytime a pipe or an outside fixture such as a cleanout or yard drain is repaired or replaced, and capping a side sewer for a demolition takes a stand-alone capping permit. Only a registered side sewer contractor may work in a public place (SMC 21.16.055). WAC 51-56, the state plumbing code, governs how the building sewer is laid. | FeeSeattle Public Utilities issues the side sewer permit and sets its fee by Director's Rule (SMC 21.16.070). | ReviewNot published by the city | Cite verified 2026-10-24 |
| Stormwater / drainage Always | New or replaced impervious surface and land disturbance are reviewed under the drainage manual this jurisdiction adopts; the threshold is the manual's. Ecology's Stormwater Management Manual for Western Washington (SWMMWW, 2024 edition) is the state floor. A municipal stormwater permittee may instead adopt a REGIONAL manual Ecology has determined equivalent, and most do — some counties publish their own, some cities publish their own, and others adopt Ecology's directly. Which manual applies is a per-jurisdiction fact and it changes the numbers: review thresholds for new plus replaced impervious surface and for land-disturbing activity differ between manuals, so read this jurisdiction's own adopting chapter before quoting one. Critical-area and closed-basin parcels get stricter review under every manual. | FeeWhere a project needs drainage review, SDCI's minimum is one hour at $292, due at intake, with further hours at $292; grading or drainage review outside a development permit starts at half an hour for each review type, and an environmentally critical area review at half an hour, plus the 5% technology fee (SMC 22.900D.145). | ReviewNot published by the city | Cite verified 2026-09-07 |
| Land-use / zoning Always | A variance, conditional use, plat or design review is a land-use decision that precedes the building permit. Triggered when a project does not conform to the strict letter of the zoning code. Variances require a hardship finding under most city codes. Design review thresholds vary (Seattle: most multifamily + non-residential >4,000 sqft; many cities: design review only in designated districts). | FeeSDCI charges land use review at $551 an hour. | ReviewNot published by the city | Cite verified 2026-05-02 |
| Tree removal Depends on scope | Trees under 6 in are not regulated, nor are invasive or nuisance species, which must be replaced. On a lot with a house, up to two trees of 6 to under 12 in may be removed in any three years. Larger trees, grove trees and listed species, and any tree of 6 in or more on a lot with no building, may not be removed unless SDCI approves them as hazardous, or in an emergency. When no development is proposed (SMC 25.11.050): trees under 6 in DSH are not regulated. On a developed lot in a Neighborhood Residential, Lowrise, Midrise, commercial or Seattle Mixed zone, no more than two Tier 4 trees may be removed in any three-year period (Tier 4: 6 in to under 12 in DSH). Tier 3 (12 in to under 24 in), Tier 2 (24 in or more, every tree in a grove, and species named by Director's Rule) and Tier 1 (heritage) trees may not be removed unless deemed hazardous or in need of emergency action, with documentation. Hazardous removal needs SDCI approval in advance, on a tree risk assessment by a registered tree service provider rating the tree Extreme or High risk (SMC 25.11.040). The Director may also allow removal of a Tier 3 or Tier 4 tree that is damaging a foundation or utilities (SMC 25.11.050.D). On an undeveloped lot, Tier 1 to 4 trees are all protected. | FeeSeattle issues no tree-removal permit when no development is proposed. | ReviewNot published by the city | Cite verified 2026-09-22 |
| Signs Always | An SDCI sign permit is needed for a sign over 5 square feet or one connected to power, and for awning work; the Sign Code limits size and number by zone. Seattle requires a sign permit from SDCI to install or alter any sign larger than 5 square feet or connected to electrical power, and to install or alter an awning, including re-covering one or changing the business name on it; the electrical permit for a lit sign is included in the sign permit. The permit requirements are in the Seattle Building Code and Title 22, and the Sign Code (SMC 23.55) sets the size, number and location of signs allowed in each zone (SMC 23.55.002). In neighborhood residential zones, temporary real estate, contractor and noncommercial signs may total 8 square feet per lot (SMC 23.55.012), and flashing and message-board signs are not allowed (SMC 23.55.020). A sign that extends over a street, sidewalk or alley may also need an SDOT street use permit. | FeeWhere a sign needs an SDCI permit (every electric sign, and a sign over 5 square feet outside the allowances of SMC 23.55.012), the fee is $193.20 for the first 32 square feet of display area plus $31.45 for each 10 square feet more up to 100, rising by size from there; a sign painted or applied directly on a wall is capped at $884. | ReviewNot published by the city | Cite verified 2026-10-24 |
Building in the City of Seattle?
Kolmo Construction is a licensed Washington general contractor — KOLMOL*753JS, bonded and insured — working throughout the City of Seattle and King County. We pull the building permits listed above and build the project. Electrical, plumbing and HVAC work, and those permits, go to licensed trade subcontractors that Kolmo manages.
How this page is built
Each row is the most-recently-verified authoritative rule on file for the City of Seattle and the listed project type. “Pending verification” means we have the 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.