Bathroom remodel permits in City of Mercer Island: fees, timeline & requirements (2026)
Everything you need to know about pulling a bathroom remodel 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..
Free lookup, no account needed — your lot polygon, zoning, setbacks and overlays, cited to City of Mercer Island's source.
When does a bathroom remodel need a permit in City of Mercer Island?
Like-for-like fixture replacement in same location with no plumbing rerouting and no new circuits: typically exempt under 2021 IRC R105.2(2)(g). Any relocation, new fixture, new circuit, or shower-pan replacement triggers permits.
How City of Mercer Island adopted this rule
The threshold comes from the state code (WAC 51.56), which City of Mercer Island adopts by reference in the provision quoted below.
“The 2021 Edition of the Uniform Plumbing Code (UPC), as adopted and amended by the State Building Code Council in WAC Chapter 51-56, as published by the International Association of Plumbing and Mechanical Officials, is adopted by reference with the following additions, deletions and exceptions. Provided, that Chapter 1, Administration, is not adopted and the Construction Administrative Code, as set forth in Chapter 17.14 MICC, shall be used in place of UPC Chapter 1, Administration. Provided, that Chapters 12 and 14 of the Uniform Plumbing Code are not adopted.”Source ↗verified 2026-04-29
Required submittals
- floor plan with fixture locations
- plumbing diagram
- electrical layout
- waterproofing detail at tub/shower
Inspection sequence
- rough-in (electrical/plumbing/mechanical)
- shower-pan/waterproofing
- insulation if walls opened
- drywall
- final
Contractor specialties needed
general, plumbing
Who can do this work in City of Mercer Island?
Kolmo Construction is a licensed Washington general contractor — KOLMOL*753JS, active through April 10, 2027, bonded and insured — working throughout City of Mercer Island and King County. Kolmo prepares the drawings and submittals, files the bathroom remodel permit with Apply via MyBuildingPermit.com., carries the project through review and inspections, and performs the construction. Call (206) 410-5100 for a City of Mercer Island bathroom remodel quote.
Notes & caveats
The Mercer Island Residential Building Permits page lists "Bathroom remodels, kitchen remodels (without removal of load bearing walls)" under the Non-Structural Interior Remodel pathway. Cross-reference: the multi-jurisdiction tip sheet referenced by Mercer Island marks bathroom/kitchen fixture replacement without plumbing-line modification as exempt for sinks and toilets, but flags that tub/shower replacement requires a permit.
Bathroom remodel permit fee — Washington baseline, not City of Mercer Island's own schedule
Worked example for a $22,000 bathroom remodel project (building permit). Your actual fee scales with project valuation.
| Building permit fee | $349.25 |
| Plan review | $227.01 |
| WA state surcharge | $6.5 |
| Estimated total | $582.76 |
Fees set by jurisdiction. Plus separate electrical, plumbing, and mechanical permits. We have not read City of Mercer Island's adopted fee schedule, so this is not City of Mercer Island's fee: it walks the standard valuation table most Washington cities adopt by reference, as a rough guide. The real numbers are in City of Mercer Island's fee schedule ↗. Impact/utility fees may apply separately.
How to apply yourself
- 1. Confirm your parcel's zoning & overlays. Run an address lookup for your City of Mercer Island bathroom remodel — 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. Respond to reviewer comments promptly.
- 5. Pay issuance fees (Fees set by jurisdiction. Plus separate electrical, plumbing, and mechanical permits.) and pick up the permit. Inspection card travels with the job.
Or have Kolmo do it
We pull bathroom remodel permits in City of Mercer Island every month. We prepare the drawings and submittals, file with Apply via MyBuildingPermit.com., handle reviewer comments, and build the project.
Licensed WA general contractor KOLMOL*753JS · bonded & insured
Bathroom remodel permits in City of Mercer Island — FAQ
When does a bathroom remodel need a permit in City of Mercer Island?
Like-for-like fixture replacement in same location with no plumbing rerouting and no new circuits: typically exempt under 2021 IRC R105.2(2)(g). Any relocation, new fixture, new circuit, or shower-pan replacement triggers permits.
How much does a bathroom remodel permit cost in City of Mercer Island?
For a $22,000 bathroom remodel project, the estimated City of Mercer Island permit fee is about $582.76 — building fee $349.25 + plan review $227.01 + surcharges. Fees scale with project valuation per the city schedule.