Deck permits in City of Mercer Island: fees, timeline & requirements (2026)
Everything you need to know about pulling a deck permit in City of Mercer Island, Washington — when one is required, what it costs, how long review takes, what documents are required, and which inspections you can expect. Cited to Apply via MyBuildingPermit.com..
When does a deck need a permit in City of Mercer Island?
Permit NOT required for sidewalks, decks and driveways constructed under IRC, not more than 30in above grade and not over any basement or story below. Decking replacement on existing decks WITHOUT changing/adding structural members and WITHOUT removing guardrails is also exempt. Per the multi-jurisdiction tip sheet, the 30-inch measurement is taken vertically to the grade below at any point within 36 inches of the outer edge of the deck. Critical-area / flood-hazard exemption rule applies.
Required submittals
- site plan with setbacks
- framing plan w/ ledger detail
- footing detail
- guard/handrail detail
Inspection sequence
- footing
- framing
- final
Contractor specialties needed
general
Notes & caveats
From MICC 17.14.010 §105.2: "Sidewalks, decks and driveways constructed under the provisions of the IRC, which are not more than 30 inches (762 mm) above grade and not over any basement or story below" are exempt. Also exempt: "Decking replacement on decks without changing or adding any other structural members or removing guardrails." Critical-area override (per MICC 17.14.010 §105.2): exemptions DO NOT apply in flood-hazard or city land-use critical areas unless work is entirely within or on the exterior envelope of a legally established existing building.
Deck permit fee estimate in City of Mercer Island
Worked example for a $18,000 deck project (building permit). Your actual fee scales with project valuation.
| Building permit fee | $293.25 |
| Plan review | $190.61 |
| WA state surcharge | $4.5 |
| Estimated total | $488.36 |
Most jurisdictions handle decks as field-inspection or simplified plan review. Computed from the City of Mercer Island fee bracket schedule · source ↗. Impact/utility fees may apply separately.
How to apply
- 1. Confirm your parcel's zoning & overlays. Run an address lookup for your City of Mercer Island deck — 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: Apply via MyBuildingPermit.com. ↗
- 4. Track review (typical: —). Respond to reviewer comments promptly.
- 5. Pay issuance fees (Most jurisdictions handle decks as field-inspection or simplified plan review.) and pick up the permit. Inspection card travels with the job.
Deck permits in City of Mercer Island — FAQ
When does a deck need a permit in City of Mercer Island?
Permit NOT required for sidewalks, decks and driveways constructed under IRC, not more than 30in above grade and not over any basement or story below. Decking replacement on existing decks WITHOUT changing/adding structural members and WITHOUT removing guardrails is also exempt. Per the multi-jurisdiction tip sheet, the 30-inch measurement is taken vertically to the grade below at any point within 36 inches of the outer edge of the deck. Critical-area / flood-hazard exemption rule applies.
How much does a deck permit cost in City of Mercer Island?
For a $18,000 deck project, the estimated City of Mercer Island permit fee is about $488.36 — building fee $293.25 + plan review $190.61 + surcharges. Fees scale with project valuation per the city schedule.