City of Issaquah building permits: fees, timelines & requirements (2026)
What needs a permit in the City of Issaquah 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 kitchen, bathroom, basement, deck, fence, siding, windows, flooring, ADU, roofing, HVAC, electrical, plumbing, addition, solar and heat pumps, and the permits beside them: demolition, right-of-way, side sewer, drainage, land use, tree removal and signs.
21 of 23 project types have authoritative rules on file · 11 always require a permit · 12 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 Issaquah's source.
Permit department
Community Planning & Development
Adopted code cycles
2021 IRC w/ WA amendments · 2021 WSEC
Resources
Construction permits
| Project | Threshold | Fee | Review days | Source |
|---|---|---|---|---|
| Kitchen remodel Depends on scope | Finish work (cabinets, counters, tile, paint) and a same-spot sink swap that replaces no valves or pipes need no permit, unless an existing accessible feature is altered. Moving plumbing, replacing a faucet or other valve, new circuits, gas or venting, or any wall or structural change needs one. A Single-Family Interior Remodel permit is required for all interior remodels. Sink/toilet replacement without plumbing-line modification is exempt; cabinets/countertops/tiling are exempt finish work; any plumbing/mechanical fixture alteration or structural change triggers the permit. | FeeAbout $1,207 for a $35,000 project, when a permit is needed | ReviewNot published by the city | Cite verified 2026-05-29 |
| Bathroom remodel Depends on scope | Finish work and swapping a prefabricated fixture, tub or shower without touching valves or pipes need no permit, unless an existing accessible feature is altered; moving plumbing, replacing a faucet or other valve or a pipe, rebuilding a site-built (tiled) shower or tub, new circuits or wall changes do. Tub and shower replacement requires a permit; sink/toilet replacement without plumbing-line modification is exempt. Processed under the Single-Family Interior Remodel permit. | FeeAbout $861 for a $22,000 project, when a permit is needed | ReviewNot published by the city | Cite verified 2026-05-29 |
| Basement finish Always | Finishing or altering a basement is an alteration of the building and needs a permit. Finishing or remodeling a basement is processed under the Single-Family Interior Remodel permit; no basement-specific square-footage exemption is published. | FeeAbout $1,331 for a $40,000 project | ReviewNot published by the city | Cite verified 2026-05-29 |
| Deck Depends on scope | A deck no more than 30 in above grade needs no permit, attached or not, and replacing decking boards alone needs none; in a flood hazard or critical area every deck needs a permit. A permit is required before any repairs, additions, or modifications to a deck more than 30 inches above grade (measured to the lowest point within 6 feet of the deck). Setbacks per IMC 18.404 by zone; decks in mapped ECA areas trigger critical-area review. | FeeAbout $724 for an $18,000 project, when a permit is needed | Review14–28 days | Cite verified 2026-05-29 |
| Fence Depends on scope | A fence up to 7 ft located in accordance with the land use and street standards needs no building permit unless the lot is in a flood hazard or critical area; taller, placed against those standards, or in such an area, it does. Residential fences do not require a building permit unless the fence is more than 6 feet in height or is in a critical area. Separately from the permit trigger, the maximum height in the front setback is 4 feet in the Single-Family/Duplex (SF-D) zone per IMC 18.700.160; other land-use restrictions may apply (IMC 18.600.090), and HOA approval may be required. | FeeAbout $312 for a $6,000 project, when a permit is needed | ReviewNot published by the city | Cite verified 2026-05-29 |
| Siding Depends on scope | Replacing non-structural siding on a house needs no permit; stucco, veneer, EIFS, structural work, or siding on a condominium or other multiunit residential building does. Non-structural siding replacement is exempt, except for EFIS (exterior finish and insulation systems), veneer, or stucco, which require a permit. | FeeAbout $724 for an $18,000 project, when a permit is needed | ReviewNot published by the city | Cite verified 2026-05-29 |
| Window replacement Depends on scope | Replacing a window with one of the same size needs no permit when no framing changes, egress is kept, safety glazing and fall protection are provided where required, and the new window meets the energy code's U-factor; a new or resized opening does. Like-for-like window/door replacement is exempt when the opening is not increased, energy efficiency (U-value) is not decreased, and egress is maintained. A new or larger opening requires a permit. | FeeAbout $381 for an $8,000 project, when a permit is needed | ReviewNot published by the city | Cite verified 2026-05-29 |
| Flooring Depends on scope | New flooring is finish work and needs no permit unless it alters an existing accessible feature; changing the subfloor or joists, or adding radiant heat, does. Interior finish work (carpet, tile) is exempt — no permit required. | FeeAbout $312 for a $6,000 project, when a permit is needed | ReviewNot published by the city | Cite verified 2026-05-29 |
| ADU / DADU Always | An ADU or DADU always needs a building permit, and usually trade permits with it. IMC 18.500.090: ADU max 1,000 sq ft GFA excluding non-living areas (garage, storage sheds, decks) — except when the excluded area IS the location of the proposed ADU. Principal unit GFA must be ≥25% greater than largest ADU on the lot. Up to TWO ADUs per lot (any combination attached/detached) allowed alongside the primary residence. Owner- occupancy NOT required (preempted by WA HB 1337). New ADUs not subject to rear-yard setback when rear abuts a public alley (unless the city plows that alley). 4-ft walkway required from ROW/driveway to ADU primary entrance. Height per IMC 18.404 form-and-intensity for the underlying zone (typically 30 ft in SF-D / SF-S / SF-SL). Parking: one additional off-street stall required per Issaquah ADU site-plan rules (may be waived for ADUs within ½ mi of frequent transit per HB 1337). | FeeAbout $3,837 for a $200,000 project | Review45–120 days | Cite verified 2026-05-16 |
| Roofing Depends on scope | In-kind re-roofing of a house needs no permit when the sheathing stays; replacing sheathing, changing the material, framing changes, skylights or rooftop units do. A permit is required for a re-roof involving structural elements — sheathing, skylights, change of roof pitch, adding/relocating mechanical units, or a roof-material change exceeding 10 lb/sq ft. In-kind re-roof without sheathing change, overlays ≤2 layers, and repairs <100 sq ft are exempt. | FeeWhere a re-roof needs a permit in Issaquah, it is a building permit priced on the value of the work: $32.39 up to $500, $32.39 plus $4.05 for each $100 more up to $2,000, $96.55 for the first $2,000 plus $19.60 for each $1,000 more up to $25,000, and $544.06 for the first $25,000 plus $14.23 for each $1,000 more up to $50,000. | ReviewNot published by the city | Cite verified 2026-05-29 |
| HVAC Depends on scope | Installing or replacing heating, cooling or ventilation equipment, gas appliances or gas piping needs a mechanical permit; portable appliances, work on the piping inside the equipment, minor part replacements and small self-contained refrigeration units do not, except outdoors in a flood hazard or critical area. A mechanical permit is required for furnaces, AC, heat pumps, gas appliances and gas piping. Mechanical work tied to a building permit is a component of it; standalone fixtures issue online. For one- and two-family dwellings the fee is 8% of the determined building permit fee for NEW CONSTRUCTION only. For remodels, additions and anything other than new construction it is a flat $62.88 per new appliance, per duct system, or for gas piping alone, with a $62.88 minimum and a $422.04 maximum; a like-for-like water heater or furnace replacement is $62.88. A separate technology fee applies. Commercial and multifamily are charged on valuation instead (Table C-2). | FeeIssaquah's mechanical permit for work on an existing house is $62.88 for each new appliance, new duct system or gas piping, $62.88 at the least and $422.04 at the most; replacing only a furnace or water heater like for like is $62.88. | ReviewNot published by the city | Cite verified 2026-05-29 |
| Electrical Always | Electrical work needs a permit, issued by WA L&I rather than the City. Electrical work requires a permit, but in Issaquah electrical permits are reviewed and issued by the Washington State Department of Labor & Industries, not the City. | FeeIssaquah charges no electrical permit fee: the City's fee sheets say electrical permits are issued and inspected by L&I, which sets and collects the fee. | ReviewNot published by the city | Cite verified 2026-05-29 |
| Plumbing Depends on scope | Stopping a leak, clearing a stoppage, resetting a toilet and swapping a prefabricated fixture in place without replacing valves or pipes need no permit; a water heater, a new or moved fixture, new piping, a replaced pipe, or a replaced faucet or other valve does, and so does a site-built (tiled) shower or tub. A plumbing permit is required for fixtures/lines, electric water-heater installs, and irrigation backflow devices (a separate over-the-counter plumbing permit is required before the work). The plumbing permit fee is 8% of the building permit fee. | FeeIssaquah's plumbing permit for work on an existing house is $31.44 for each new or moved fixture, and $31.44 per dwelling to re-pipe its water lines, $62.88 at the least and $422.04 at the most; replacing only a water heater like for like is $62.88; each backflow device is $67.91 plus a $37.72 issuance fee. | ReviewNot published by the city | Cite verified 2026-05-29 |
| Addition Always | An addition enlarges the building and needs a permit. A permit is required for all single-family/duplex new construction and additions; no exemption is published. Setback / form / intensity per IMC 18.404. | FeeAbout $2,705 for a $120,000 project | Review45–120 days | Cite verified 2026-05-29 |
| Solar (rooftop PV) Always | A solar PV system needs an electrical permit from WA L&I. A rooftop system on a house meeting every criterion of the City's PV exemption needs no City building permit. | FeeThe electrical permit comes from L&I, at L&I's fees. A rooftop system that does not meet every criterion of the City's PV exemption needs a City building permit, priced on the value of the work: $32.39 up to $500, and $96.55 for the first $2,000 plus $19.60 for each $1,000 more, up to $25,000. | ReviewNot published by the city | Cite verified 2026-10-02 |
| Heat pump Depends on scope | Installing or replacing a heat pump needs a City mechanical permit and an L&I electrical permit; a portable unit, work on the piping inside the unit, a minor part replacement or a small self-contained unit does not need the mechanical permit, except outdoors in a flood hazard or critical area. | FeeIssaquah's mechanical permit for work on an existing house is $62.88 for each new appliance, $62.88 at the least and $422.04 at the most, plus a separate technology fee (Mechanical Fee Schedule, Table C-1, updated 1/1/2026). | ReviewNot published by the city | Cite verified 2026-10-02 |
Ancillary & non-building permits
| Project | Threshold | Fee | Source |
|---|---|---|---|
| Demolition Always | Demolishing a building or structure needs a permit; the site must then be cleared and restored within 30 days. 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. | FeeIssaquah's demolition permit is $410.80 on its Site Work and Utility Permit Fee Schedule (effective April 7, 2026), with the City's technology surcharge added (IMC 3.66.020). | 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. | FeeIssaquah's street use permit is $3,026.38, a single-day traffic control plan $363.17, and a pavement cut $132.03 for up to 50 square feet or $198.03 up to 100 (twice that if the pavement is under 3 years old), on its Site Work and Utility Permit Fee Schedule (effective April 7, 2026); the City's technology surcharge is added (IMC 3.66.020). | Cite verified 2026-09-07 |
| Side sewer Always | Where the City owns the sewer, building a side sewer or any modification of one needs a City permit before work starts, with no minimum length; where a district owns the main, that district issues it. Where the City of Issaquah owns the sewer, a City side sewer permit is required before any work starts to build a side sewer or to modify an existing one, on private property or in the right-of-way (IMC 13.40.020), so any repair counts, with no minimum length. A permit for work only on private property may go to the owner or their licensed side sewer contractor; one that includes work in a public way goes only to a licensed side sewer contractor. Where a sewer district owns the main, that district issues the permit under its own code, so confirm the owner of the main before applying. WAC 51-56, the state plumbing code, governs how the building sewer is laid. | FeeWhere the City serves the lot, Issaquah's utility service application is $410.80, and a new connection pays the City's sewer general facilities charge, $4,410 per residential customer equivalent, while King County bills its own sewer capacity charge (Site Work and Utility Permit Fee Schedule, effective April 7, 2026). | 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. | FeeIssaquah's grading permit is $1,210.56 for less than an acre; street and utility plan review for a remodel or site alteration is $3,631.67, NPDES review $3,631.67, and a stormwater adjustment $4,236.93. | Cite verified 2026-09-06 |
| 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). | FeeIssaquah's Land Use Fee Schedule (effective April 7, 2026) lists a pre-application conference at $3,026.38 (up to two meetings) or $311.29 for one meeting on an ADU or a new house, a deviation of standards at $4,236.93, a variance at $30,263.82 outside a critical area or $36,316.58 in one (plus hearing examiner costs), SEPA review at $6,052.23, a shoreline exemption at $1,210.56, a lot line adjustment at $5,084.33, a home business review at $635.59, and a zoning verification letter at $363.17. | Cite verified 2026-05-16 |
| Tree removal Depends on scope | In Issaquah a significant tree is 6 in DBH or more, an alder or cottonwood 8 in; a species on the King County noxious weed list is not one. Removing a significant tree needs City approval: a tree permit, or approval as part of a landscape, grading, site work or building permit. A landmark tree, over 30 in, needs a tree permit, considered only for a nuisance or hazardous tree. No tree may come down on a vacant lot before development is approved, or in a critical area or a native growth protection easement, except as the tree code allows. A smaller tree that nothing else protects needs no approval; there is no yearly allowance. A tree in the street right-of-way is a street tree. A Tree Permit is required in most cases for removal, excessive pruning (IMC 18.102.090), and creating a wildlife snag. A significant tree is 6" DBH or greater, or 8" DBH or greater for alder and cottonwood; DBH is measured 4.5 feet above average grade. The most common exemption is removal of nonsignificant trees not protected by any other means. Replacement is required at not less than 1:1 and must provide canopy coverage equal to or greater than the tree(s) removed (IMC 18.812.060) — waivable if the site still meets canopy targets after removal. | FeeIssaquah's tree removal permit is $180, or $726.34 in a critical area; a retroactive permit is $726.34, or $1,452.68 in a critical area, and the permit for hazardous trees is listed without a fee. | Cite verified 2026-08-11 |
| Signs Always | A sign permit is needed to put up, reface, alter or repair a sign, and a temporary sign agreement for a temporary sign; the code lists the signs that need neither. Issaquah requires a sign permit from the Director to erect, re-erect, construct, reface, alter or repair a sign, unless its sign code says the sign needs none, with a separate permit for each sign; temporary signs need a temporary sign agreement instead (LUC 18.612.160). The permanent signs allowed without a permit, such as directional and informational signs, drive-through selection signs and home business signs, must meet the conditions listed for each type and be nonelectric and unlit unless the code allows otherwise (LUC 18.612.070). | FeeIssaquah's permanent sign permit is $605.28 for a wall or other sign (Type 1), $907.91 for a freestanding or monument sign (Type 2), and $211.85 for each additional sign; a sign variance is $9,684.41 plus hearing examiner costs. | Cite verified 2026-10-24 |
Review days: not published by the city for any permit in this table.
Building in the City of Issaquah?
Kolmo Construction is a licensed Washington general contractor — KOLMOL*753JS, bonded and insured — working throughout the City of Issaquah 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 Issaquah and the listed project type.
See the data-quality leaderboard for how we keep these current, or run an address-specific lookup on the main permits page.