Plumbing permits in Issaquah: fees, timeline & requirements (2026)
Everything you need to know about pulling a plumbing permit in Issaquah, Washington — when one is required, what it costs, how long review takes, what documents are required, and which inspections you can expect. Cited to Community Planning & Development.
Free lookup, no account needed — the office that issues the permit at your address, cited to Issaquah's source.
When does plumbing work need a permit in Issaquah?
A plumbing permit is required for fixtures/lines, electric water-heater installs, and irrigation backflow devices (a separate over-the-counter plumbing permit is required before the work). The plumbing permit fee is 8% of the building permit fee.
In the source's own words
“A backflow device is required for any irrigation system. The contractor must obtain a separate over-the-counter plumbing permit before performing the work.”Source ↗verified 2026-05-29
Required submittals
- Fixture count + DFU calc for repipes
- Water heater specs
- Sewer line plan if site work involved
Inspection sequence
- Rough-in / pressure test
- Final
Contractor specialties needed
Plumber
Who can do this work in Issaquah?
Kolmo Construction is a licensed Washington general contractor — KOLMOL*753JS, active through April 10, 2027, bonded and insured — working throughout Issaquah and King County. Kolmo manages the plumbing job from start to finish: a licensed plumbing contractor performs the work and the permit, and Kolmo coordinates the scope, schedule, inspections and any related construction. Call (206) 410-5100 for an Issaquah plumbing quote.
Notes & caveats
Water heater: T&P relief, expansion tank required if pressure >80psi or check valve installed. Sewer line: cleanouts at every 100ft + change of direction. Backwater valve required in flood zones.
How to apply yourself
- 1. Check who issues the permit. Run an address lookup for your plumbing work in Issaquah — we'll confirm which office issues the permit at that address.
- 2. Assemble submittals: the 3 documents under Required submittals above.
- 3. Submit through the city portal: Community Planning & Development ↗
- 4. Track review. Respond to reviewer comments promptly.
- 5. Pay issuance fees (Issaquah's fee schedule sets them) and pick up the permit. Inspection card travels with the job.
Or have Kolmo do it
Kolmo runs the job: a licensed plumbing contractor does the plumbing work and pulls the permit, and Kolmo coordinates the scope, schedule, inspections and any related construction.
Licensed WA general contractor KOLMOL*753JS · bonded & insured
Plumbing permits in Issaquah — FAQ
When does plumbing work need a permit in Issaquah?
A plumbing permit is required for fixtures/lines, electric water-heater installs, and irrigation backflow devices (a separate over-the-counter plumbing permit is required before the work). The plumbing permit fee is 8% of the building permit fee.
How much does a plumbing permit cost in Issaquah?
Issaquah's plumbing permit for work on an existing house is $31.44 for each new or moved fixture, and $31.44 per dwelling to re-pipe its water lines, $62.88 at the least and $422.04 at the most; replacing only a water heater like for like is $62.88; each backflow device is $67.91 plus a $37.72 issuance fee. For new construction it is 8% of the building permit fee. A separate technology fee applies. Apply via https://mybuildingpermit.com.