Plumbing permits in City of Mercer Island: fees, timeline & requirements (2026)

Everything you need to know about pulling a plumbing 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..

Permit required?
Yes — see threshold below
Permit fee
Plumbing permit fees by fixture count. Standard residential ~$80-$250.
Review timeline

When does a plumbing need a permit in City of Mercer Island?

WAC 51-56 (2021 UPC) requires plumbing permit for installation, replacement, or relocation of any plumbing fixture, water heater, or piping. Like-for-like faucet replacement is exempt.

Required submittals

  • fixture count + DFU calc for repipes
  • water heater specs
  • sewer line plan if site work involved

Inspection sequence

  1. rough-in / pressure test
  2. final

Contractor specialties needed

plumbing

Notes & caveats

From multi-jurisdiction tip sheet (Mercer Island): "Bathroom and kitchen fixture replacements without plumbing line modifications such as sinks and toilets" are exempt. However: "Tub and shower replacement does require a permit." Hose bibs and drinking fountains (per the same tip sheet) require a permit. Backflow prevention devices require a permit.

Plumbing permit fee estimate in City of Mercer Island

Worked example for a $6,000 plumbing project (plumbing permit). Your actual fee scales with project valuation.

Building permit fee$150
Plan review$97.5
WA state surcharge$4.5
Estimated total$252

Multi-fixture (bathroom remodel, repipe section): ~$150 Computed from the City of Mercer Island fee bracket schedule · source ↗. Impact/utility fees may apply separately.

How to apply

  1. 1. Confirm your parcel's zoning & overlays. Run an address lookup for your City of Mercer Island plumbing — we'll pull your specific lot polygon, zoning, setbacks, and any shoreline/ECA/historic overlays.
  2. 2. Assemble submittals (3).
  3. 3. Submit through the city portal: Apply via MyBuildingPermit.com.
  4. 4. Track review (typical: ). Respond to reviewer comments promptly.
  5. 5. Pay issuance fees (Plumbing permit fees by fixture count. Standard residential ~$80-$250.) and pick up the permit. Inspection card travels with the job.

Plumbing permits in City of Mercer Island — FAQ

When does a plumbing need a permit in City of Mercer Island?

WAC 51-56 (2021 UPC) requires plumbing permit for installation, replacement, or relocation of any plumbing fixture, water heater, or piping. Like-for-like faucet replacement is exempt.

How much does a plumbing permit cost in City of Mercer Island?

For a $6,000 plumbing project, the estimated City of Mercer Island permit fee is about $252 — building fee $150 + plan review $97.5 + surcharges. Fees scale with project valuation per the city schedule.

City of Mercer Island resourcesPermit portal ↗Fee schedule ↗