Basement finish permits in Issaquah: fees, timeline & requirements (2026)
Everything you need to know about pulling a basement finish permit in Issaquah, Washington — when one is required, what it costs, how long review takes, what documents are required, and which inspections you can expect. Cited to Community Planning & Development.
Free lookup, no account needed — your lot polygon, zoning, setbacks and overlays, cited to Issaquah's source.
When does a basement finish need a permit in Issaquah?
Finishing or remodeling a basement is processed under the Single-Family Interior Remodel permit; no basement-specific square-footage exemption is published.
In the source's own words
“Apply for a Single-Family Interior Remodel Permit when remodeling a residential home.”Source ↗verified 2026-05-29
Required submittals
- Floor plan w/ egress windows + ceiling heights
- Electrical layout
- Plumbing diagram
- Mechanical / HVAC plan
- WSEC compliance form (newly conditioned space)
- Smoke/CO alarm locations
Inspection sequence
- Rough-in (electrical/plumbing/mechanical)
- Framing
- Insulation
- Drywall
- Final
Contractor specialties needed
General contractor · Plumber · Mechanical contractor
Who can do this work in Issaquah?
Kolmo Construction is a licensed Washington general contractor — KOLMOL*753JS, active through April 10, 2027, bonded and insured — working throughout Issaquah and King County. Kolmo prepares the drawings and submittals, files the basement finish permit with Community Planning & Development, carries the project through review and inspections, and performs the construction. Call (206) 410-5100 for an Issaquah basement finish quote.
Notes & caveats
Construction permit required for any habitable space addition. Smoke + CO alarms required (R314, R315). Any new circuits, plumbing fixtures, or HVAC requires trade permits.
Basement finish permit fee estimate in Issaquah
Worked example for a $40,000 basement finish project (building permit). Your actual fee scales with project valuation.
| Building permit fee | $757.51 |
| Plan review | $492.38 |
| Technology surcharge | $74.99 |
| WA state surcharge | $6.50 |
| Estimated total | $1,331.38 |
Issaquah prices a basement finish's building permit 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. Plan review adds 65% of that fee, a 6% technology surcharge is added to both, and the state building code fee is $6.50. Plumbing is $31.44 for each new or moved fixture and mechanical $62.88 for each new appliance or duct system, each $62.88 at the least and $422.04 at the most, with a separate technology fee. Electrical permits come from L&I, not the City, at L&I's fees. Apply via mybuildingpermit.com. Computed from Issaquah's adopted fee schedule · source ↗. Land use, fire and engineering review, intake, impact and utility fees, where they apply, are charged separately.
How to apply yourself
- 1. Confirm your parcel's zoning & overlays. Run an address lookup for your Issaquah basement finish — we'll pull your specific lot polygon, zoning, setbacks, and any shoreline/ECA/historic overlays.
- 2. Assemble submittals (6).
- 3. Submit through the city portal: Community Planning & Development ↗
- 4. Track review. Respond to reviewer comments promptly.
- 5. Pay issuance fees (about $1,331 for a $40,000 project) and pick up the permit. Inspection card travels with the job.
Or have Kolmo do it
Kolmo prepares the drawings and submittals, files with Community Planning & Development, handles reviewer comments, and builds the project.
Licensed WA general contractor KOLMOL*753JS · bonded & insured
Basement finish permits in Issaquah — FAQ
When does a basement finish need a permit in Issaquah?
Finishing or remodeling a basement is processed under the Single-Family Interior Remodel permit; no basement-specific square-footage exemption is published.
How much does a basement finish permit cost in Issaquah?
For a $40,000 basement finish project, the estimated Issaquah permit fee is about $1,331.38 (building fee $757.51 + plan review $492.38 + surcharges) from Issaquah's adopted fee schedule. Land use, fire and engineering review, intake, impact and utility fees, where they apply, are charged separately.