City of Sammamish building permits: fees, timelines & requirements (2026)
What needs a permit in City of Sammamish 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 daily 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).
21 of 24 project types have authoritative rules on file · 12 always require a permit · 9 depend on the scope · 0 do not.
Get your lot in 3D with zoning, setbacks, and the exact permits your project needs — cited to City of Sammamish's source.
Permit department
Apply via MyBuildingPermit.com.
Adopted code cycles
2021 IRC w/ WA amendments · 2021 WSEC
Resources
Construction permits
| Project | Permit? | Threshold | Fee | Review days | Source |
|---|---|---|---|---|---|
| Kitchen remodel | Depends on scope | No permit for cabinets, counters, paint or tile. A permit once you move plumbing, add circuits, run gas or change walls. Finish work (cabinets, countertops, tile, paint) is exempt; moving walls or adding/relocating plumbing/electrical triggers a Single-Family Residential Remodel permit. A Sewer Availability Certificate is required when the project exceeds 50% of the assessed value or adds plumbing fixtures. | Fees set by jurisdiction. WA Building Code Council surcharge: $6.50 per building permit. Trade permits separate. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-09-24 |
| Bathroom remodel | Depends on scope | No permit for tile, paint or a same-spot fixture swap. A permit once plumbing moves, circuits are added or the tub or shower goes. Bathroom remodels are processed as a Single-Family Residential Remodel permit. A Sewer Availability Certificate is required when the project exceeds 50% of the assessed value or includes additional plumbing fixtures; like-for-like finish work is exempt. | Fees set by jurisdiction. Plus separate electrical, plumbing, and mechanical permits. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-09-24 |
| Basement finish | Always | Finishing a basement into habitable space needs a building permit; egress and ceiling height are the usual review items. 2021 IRC R310: every sleeping room below grade requires emergency escape and rescue opening (egress window). Min sill height 44in, min net clear opening 5.7 sq ft (5.0 grade-floor), min width 20in, height 24in. Ceiling height min 7ft (R305). Entire newly conditioned area must comply with WSEC R402. | Plan-review fee scales with valuation. State surcharge $6.50. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-05-29 |
| Deck | Depends on scope | Exempt only when all hold: 200 sq ft or under, 30 in or under at any point, not attached, and not serving a required exit door. Plans are required for new or enlarged decks. A deck is exempt only if it is ≤200 sq ft, ≤30 inches above grade at any point, not attached to a dwelling, and does not serve a required exit door (adopted 2021 WA IRC R105.2(10)). Deck repair that does not expand or change the footprint needs no site plan. | Most jurisdictions handle decks as field-inspection or simplified plan review. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-09-24 |
| Fence | Depends on scope | No permit for a fence 7 ft or under. A building permit is not required for a fence 7 feet or less in height (adopted 2021 WA IRC R105.2(2), adopted by SMC 16.05.080); taller fences require a permit. Zoning height/setback limits still apply. | Typically no fee unless permit required. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-09-24 |
| Siding | Depends on scope | Like-for-like siding is an ordinary repair and exempt. Changing sheathing, adding insulation, or changing the weather barrier needs a permit. 2021 IRC R105.2(1)(g) exempts "ordinary repairs" — like-for-like siding replacement on existing structure. Permit required if changing structural sheathing, adding insulation that affects WSEC compliance, or modifying weather-resistive barrier (WRB) detailing. | Typically minimal fee — like-for-like usually exempt. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-05-29 |
| Window replacement | Depends on scope | Same-size replacement in the existing opening is exempt. A new, enlarged or reduced opening, a header change, or anything that affects a bedroom escape window needs a permit. 2021 IRC R105.2(1)(g) exempts like-for-like window replacement (same rough opening, same R-value class). Permit required for: new openings, enlarged/reduced openings, egress-affecting changes (R310), and any change that crosses a structural element. | Like-for-like usually no permit fee. Structural changes scale with valuation. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-05-29 |
| Flooring | Depends on scope | Floor finishes are exempt. Modifying the subfloor or joists, or installing radiant heat, needs a permit. 2021 IRC R105.2(1)(j) exempts floor finishes (carpet, vinyl, hardwood, tile). Permit required if subfloor structure is modified, joists altered, or radiant heat installed. | No permit fee for surface flooring. Apply via https://mybuildingpermit.com. | Not 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. Up to two ADUs per lot are allowed (with a detached single-family residence). A detached ADU can be a maximum of 1,000 square feet; an attached ADU can be up to 50% of the size of the single-family residence or 1,000 square feet, whichever is larger. Detached ADU height is capped at 24 ft. No additional parking is required if the property already has four or more spaces. Owner-occupancy is not required (HB 1337). | Full Construction Permit (Addition/Alteration) fees. A new ADU connection commonly also triggers a ONE-TIME sewer and/or water connection charge from the utility that serves the property — called a general facility charge, a capacity charge or a system development charge depending on the utility. WHICH UTILITY AND WHICH CHARGE IS A PER-PROPERTY FACT, not a city or county one, and a single lot can sit inside a city for permitting and outside its sewer district. Ask the utility that will actually serve the ADU; this charge is often the largest single line in an ADU budget after construction. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-09-24 |
| Roofing | Not verified | Whether a re-roof needs a permit depends on this city's own code, and cities differ: some exempt a like-for-like re-roof, some require a permit only when sheathing is replaced, some for every re-roof. Kolmo has not verified this city — ask its building department. Whether a re-roof needs a building permit is set by each city's own administrative code (the chapter it adopts with the residential code), and cities differ: some exempt a roof recover or a like-for-like replacement, some require a permit only when the sheathing is modified or replaced, and some require one for every re-roof. Kolmo has not verified this city's rule; ask its building department. Re-roofing requirements themselves are in IRC R908. | Flat fee or valuation-based, per the city's fee schedule. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-05-29 |
| HVAC | Always | Any mechanical equipment install, replacement or relocation needs a mechanical permit. WAC 51-52 (2021 IMC) and WAC 51-56 (2021 UPC) require mechanical permit for any equipment install, replacement, or relocation. WSEC R403 requires sizing per Manual J/S/D for new equipment. | Mechanical permit + electrical permit (if new circuit) + plumbing permit (if condensate to drain). Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-05-29 |
| Electrical | Depends on scope | New circuits, panel work and fixtures need an electrical permit; minor like-in-kind work is exempt. New circuits, panel work, and fixtures require an Electrical permit; minor work (replacing overcurrent devices, wiring under 25 volts, minor repair) is exempt under the adopted code. Electrical permits route through MyBuildingPermit. | Electrical permit fees are set by circuit count and service size in the issuing agency's fee schedule. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-09-24 |
| Plumbing | Depends on scope | Adding or relocating a fixture, or water and drain piping, needs a plumbing permit. Stopping leaks, clearing stoppages, and resetting a toilet are exempt. Fixture additions/relocations and water/drain piping require a plumbing permit; stopping leaks, clearing stoppages, and removing/reinstalling water closets (without replacing valves/pipes/fixtures) are exempt. A Residential Fixture Count form is required; a Sewer Availability Certificate is required when fixtures are added. | Plumbing permit fees are set by fixture count in the city's fee schedule. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-09-24 |
| Addition | Always | Adding floor area always needs a building permit. Single-family/duplex additions require a building permit (MBP: Building → Single-Family Residential → Structure Addition). Demolitions, pools, retaining walls, and detached structures require separate permits. A Sewer Availability Certificate is required when the project exceeds 50% of the assessed value or adds plumbing fixtures. | Plan-review fee scales with valuation per UBC Table 1-A. State surcharge $6.50 per building permit. Trade permits (E/P/M) separate. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-09-24 |
Ancillary & non-building permits
| Project | Permit? | Threshold | Fee | Review days | Source |
|---|---|---|---|---|---|
| Demolition | Always | Demolishing a structure or a substantial part of one 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. | Demolition fees commonly charged as flat fee or by structure size. State surcharge $6.50 applies. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-05-29 |
| Right-of-way | Always | Any work in or occupation of the public right of way needs a right-of-way permit from public works. 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. | Right-of-way permit fees vary by city: a base fee for a residential driveway or curb cut, plus a per-day occupancy charge if the street is obstructed. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-09-06 |
| Side sewer | Always | A new side-sewer connection, a repair beyond about 2 ft, relining or capping needs a permit from whichever utility owns the main. The side-sewer permit is issued by whichever utility owns the sanitary sewer — the city, a sewer or water district, or a regional utility — under that utility's own code, with WAC 51-56 (2021 UPC) governing how the building sewer is laid. WHICH UTILITY IS A PER-PROPERTY FACT: a lot can sit inside a city for permitting and outside its sewer district, so confirm the owner of the main before applying. Triggered by a new connection, repair of more than about 2 ft of pipe, relining (CIPP), or capping at the property line for a demolition. | Side-sewer permit fees are set by the utility that owns the main; some add a depth-based surcharge. Utility-issued, not building-permit-issued. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-09-24 |
| 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. | Drainage review fees are commonly tiered by project size in the city's fee schedule. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-05-29 |
| 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). | Land-use fees vary widely; a variance usually carries an application fee plus cost recovery for the hearing examiner. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-05-29 |
| Tree removal | Not verified | This city protects trees under its own ordinance and Kolmo has not verified the size threshold. Ask the city before cutting; some cities prohibit removal above a size rather than permit it. Triggered by removal of a tree that the city's own tree ordinance protects — commonly defined by a diameter at breast or standard height, a listed-species table, a grove or heritage designation, or a canopy-cover target. This baseline row carries NO verified local threshold; read the city's tree chapter before quoting a number. Some cities do not permit removal above a size at all — they prohibit removal of regulated trees outside enumerated exceptions, so a "permit required at X inches" reading is wrong there. | Tree-removal permit fees are set per permit or per tree in the city's fee schedule; some cities require replacement bonds. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-05-29 |
| Signs | Always | Permanent signs need a sign permit; small temporary residential signs are usually exempt. City sign code (typically Title 22 or 23) governs. Wall, freestanding, projecting, awning, and electronic message signs all require permits. Most cities exempt small temporary residential signs (real-estate, political) under area thresholds (~6 sqft). | Sign permit fees are set in the city's fee schedule, plus an electrical sub-permit for an illuminated sign. Apply via https://mybuildingpermit.com. | Not published by the city | Cite verified 2026-05-29 |
Building in City of Sammamish?
Kolmo Construction is a licensed Washington general contractor — KOLMOL*753JS, bonded and insured — working throughout City of Sammamish and King County. We pull the permits listed above and build the project.
How this page is built
Each row is the most-recently-verified authoritative rule on file for City of Sammamish and the listed project type. “Pending verification” means we have City of Sammamish 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.