Addition permits in Lynnwood: fees, timeline & requirements (2026)
Everything you need to know about pulling a home addition permit in Lynnwood, Washington — when one is required, what it costs, how long review takes, what documents are required, and which inspections you can expect. Cited to Lynnwood Development & Business Services.
Free lookup, no account needed — your lot polygon, zoning, setbacks and overlays, cited to Lynnwood's source.
When does a home addition need a permit in Lynnwood?
2021 IRC R105.1 requires permits for "construction, enlargement, alteration, repair, movement, removal, conversion, or demolition" of structures. Additions are never exempt under R105.2. Footprint additions trigger zoning compliance (setbacks, lot coverage, height); vertical additions trigger structural review for the existing foundation/wall framing. WSEC R402-R403 applies to new conditioned area. SEPA threshold typically ≥12,000 sq ft total floor area (RCW 43.21C).
How Lynnwood adopted this rule
The threshold comes from the state code (WAC 51.51), which Lynnwood adopts by reference in the provision quoted below.
“As amended by the provisions of this chapter and the State of Washington Building Code Council, under Chapter 51-50 WAC, the latest edition of the International Building Code, published by the International Code Council, together with Appendices E, G, and J, one copy of which, along with the State of Washington Building Code Council’s amendments, shall be on file in the office of the Lynnwood city clerk, are adopted by reference. (Ord. 3404 § 3 (Att. A), 2021; Ord. 3396 § 3, 2021; Ord. 3306 § 1 (Exh. 1), 2018; Ord. 3196 § 3, 2016; Ord.”Source ↗verified 2026-04-29
Required submittals
- Site plan with north arrow, property lines, setbacks, existing + proposed structures, lot coverage calculation
- Floor plan existing and proposed (dimensioned, 1/4" = 1' min)
- Elevations all affected sides (existing + proposed, height-to-grade)
- Foundation plan + footing details (if footprint addition)
- Framing plan (floor + roof + lateral)
- Wall section with insulation values per WSEC
- Structural calculations (when ≥500 sq ft addition or out of IRC prescriptive envelope)
- WSEC compliance form (Energy Code Compliance Certificate)
- Manual J HVAC sizing calculation for new conditioned area
- Window/door schedule with NFRC U-factor and SHGC values
- Soils report if footing on slope or expansive soils
Inspection sequence
- Foundation/footing
- Plumbing rough-in
- Electrical rough-in
- Mechanical rough-in
- Framing
- Insulation
- Drywall
- Final
Contractor specialties needed
General contractor
Who can do this work in Lynnwood?
Kolmo Construction is a licensed Washington general contractor — KOLMOL*753JS, active through April 10, 2027, bonded and insured — working throughout Lynnwood and Snohomish County. Kolmo prepares the drawings and submittals, files the home addition permit with Lynnwood Development & Business Services, carries the project through review and inspections, and performs the construction. Call (206) 410-5100 for a Lynnwood home addition quote.
Notes & caveats
From Lynnwood Online Permit Center: "Apply for Building, Development Engineering, Electrical, Fire, and Land Use Permits" via the city portal. All applications/inspections handled through the online dashboard. "Each permit type has different requriements and review periods" — see Applications & Checklists page for current review timelines. Inspection request cutoff: 4:00pm next-business-day; most inspections 8am-12pm. Note: Lynnwood issues electrical permits directly (unlike some WA cities that defer to L&I).
Addition permit fee estimate in Lynnwood
Worked example for a $120,000 home addition project (building permit). Your actual fee scales with project valuation.
| Building permit fee | $2,019.11 |
| Plan review | $1,312.42 |
| Technology surcharge | $83.29 |
| WA state surcharge | $6.50 |
| Estimated total | $3,421.32 |
Lynnwood prices an addition's building permit on the value of the work, by the ICC valuation table or the square footage, whichever is greater: $1,181.86 for the first $50,000 plus $12.62 for each $1,000 more up to $100,000, and $1,812.71 for the first $100,000 plus $10.32 for each $1,000 more up to $500,000. Plan review is 65% of that fee. Plumbing and mechanical permits for a remodel are each $257 for up to 4 fixtures or pieces of equipment and $22 for each one more, and the City, not L&I, issues the electrical permit: $147 for up to 10 circuits added or altered, $15 for each more circuit up to a $200 total. A 2.5% technology fee is added (LMC 3.104). Computed from Lynnwood'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 home addition in Lynnwood — we'll pull your specific lot polygon, zoning, setbacks, and any shoreline, critical-area or historic overlays.
- 2. Assemble submittals: the 11 documents under Required submittals above.
- 3. Submit through the city portal: Lynnwood Development & Business Services ↗
- 4. Track review. Respond to reviewer comments promptly.
- 5. Pay issuance fees (about $3,421 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 Lynnwood Development & Business Services, handles reviewer comments, and builds the project.
Licensed WA general contractor KOLMOL*753JS · bonded & insured
Addition permits in Lynnwood — FAQ
When does a home addition need a permit in Lynnwood?
2021 IRC R105.1 requires permits for "construction, enlargement, alteration, repair, movement, removal, conversion, or demolition" of structures. Additions are never exempt under R105.2. Footprint additions trigger zoning compliance (setbacks, lot coverage, height); vertical additions trigger structural review for the existing foundation/wall framing. WSEC R402-R403 applies to new conditioned area. SEPA threshold typically ≥12,000 sqft total floor area (RCW 43.21C).
How much does a home addition permit cost in Lynnwood?
For a $120,000 home addition project, the estimated Lynnwood permit fee is about $3,421.32 (building fee $2,019.11 + plan review $1,312.42 + surcharges) from Lynnwood's adopted fee schedule. Land use, fire and engineering review, intake, impact and utility fees, where they apply, are charged separately.