Addition permits in Kent: fees, timeline & requirements (2026)
Everything you need to know about pulling a home addition permit in Kent, Washington — when one is required, what it costs, how long review takes, what documents are required, and which inspections you can expect. Cited to Kent Economic and Community Development.
Free lookup, no account needed — your lot polygon, zoning, setbacks and overlays, cited to Kent's source.
When does a home addition need a permit in Kent?
A residential building permit is required for most construction, alteration, or repair work — including changing a building's occupancy, structure, or living space. Intake fees are billed when the submittal is deemed complete (pay within 15 days); issuance fees are due before the permit is issued.
In the source's own words
“Changing a building's occupancy, structure or living space.”Source ↗verified 2026-05-29
Required submittals
- Site plan
- Fully dimensioned floor plan for each floor (label each room/area with intended use)
- Construction plans
- Energy code calcs (2021 WSEC-R)
Inspection sequence
- Foundation/footing
- Plumbing rough-in
- Electrical rough-in
- Mechanical rough-in
- Framing
- Insulation
- Drywall
- Final
Contractor specialties needed
General contractor · Plumber · Mechanical contractor
Who can do this work in Kent?
Kolmo Construction is a licensed Washington general contractor — KOLMOL*753JS, active through April 10, 2027, bonded and insured — working throughout Kent and King County. Kolmo prepares the drawings and submittals, files the home addition permit with Kent Economic and Community Development, carries the project through review and inspections, and performs the construction. Call (206) 410-5100 for a Kent home addition quote.
Notes & caveats
2021 IRC R301 governs framing. WSEC R402.1 sets envelope requirements. New conditioned space requires Manual J HVAC sizing. Lateral load path continuity required for vertical additions.
Addition permit fee estimate in Kent
Worked example for a $120,000 home addition project (building permit). Your actual fee scales with project valuation.
| Building permit fee | $2,491.61 |
| Plan review | $1,619.55 |
| Technology surcharge | $123.33 |
| WA state surcharge | $6.50 |
| Estimated total | $4,240.99 |
Kent prices an addition's building permit on the value of the work: $881.32 for the first $25,000 plus $22.75 for each $1,000 more up to $50,000, $1,450.35 for the first $50,000 plus $15.78 for each $1,000 more up to $100,000, and $2,238.81 for the first $100,000 plus $12.64 for each $1,000 more up to $500,000. Intake fees are billed once the submittal is complete, and the rest before the permit issues. The plumbing and mechanical permits are priced separately, and the City's posted fee documents (its 2026 building permit fee table and land use fees) list neither, so the Permit Center (253-856-5300) quotes them. Electrical permits come from L&I, at L&I's fees. Apply through the City of Kent Permit Portal (sso.kentwa.gov). Computed from Kent'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 Kent home addition — we'll pull your specific lot polygon, zoning, setbacks, and any shoreline/ECA/historic overlays.
- 2. Assemble submittals (4).
- 3. Submit through the city portal: Kent Economic and Community Development ↗
- 4. Track review. Respond to reviewer comments promptly.
- 5. Pay issuance fees (about $4,241 for a $120,000 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 Kent Economic and Community Development, handles reviewer comments, and builds the project.
Licensed WA general contractor KOLMOL*753JS · bonded & insured
Addition permits in Kent — FAQ
When does a home addition need a permit in Kent?
A residential building permit is required for most construction, alteration, or repair work — including changing a building's occupancy, structure, or living space. Intake fees are billed when the submittal is deemed complete (pay within 15 days); issuance fees are due before the permit is issued.
How much does a home addition permit cost in Kent?
For a $120,000 home addition project, the estimated Kent permit fee is about $4,240.99 (building fee $2,491.61 + plan review $1,619.55 + surcharges) from Kent's adopted fee schedule. Land use, fire and engineering review, intake, impact and utility fees, where they apply, are charged separately.