Plumber in Redmond, WA: permits, water lines and how to hire

Redmond has the youngest housing of the cities on this site. Census Bureau survey data for 2020 to 2024 put the median year built at 1993, with about 22 percent of homes built from 2010 to 2019 and about 5 percent in 2020 or later (ACS table B25034 via Census Reporter). Still, about 20 percent date from the 1980s and 16 percent from the 1970s. Newer homes tend to have plastic supply and drain piping and tankless or high-efficiency water heaters; older ones may be on their second or third water heater and original side sewer.

Redmond's rules are broader than some neighbors'. Its electrical, mechanical and plumbing permit page lists projects that need a mechanical, electrical or plumbing permit, including:

• New or replacement water heaters, heat pumps or furnaces
• New or replacement toilet, sink or shower fixtures
• Installation of a three-compartment sink or grease interceptor

The list is not exhaustive, and each application form spells out what it covers. Residential plumbing permits can be applied for online through the Redmond ePermitting Service (REPS). Fees are based on the value of construction and fixture counts. Inspections must be requested before any work is covered, and a permit stays valid for 365 days without inspections. Redmond designs plumbing to the Uniform Plumbing Code. Compare this with Bellevue, where a like-for-like fixture swap does not need a permit.

Redmond's Wastewater Maintenance Division maintains 234 miles of sewer pipe, 7,650 manholes and 22 lift stations, according to its Wastewater/Sewer page. It camera inspects the public system every seven years and cleans all pipes every five years. That work covers the public system. The city's homeowner page tells residents that a blocked side sewer can back up into the house and yard, most often from roots, wipes and grease, and to ask a plumber or contractor to determine whether the side sewer is blocked and make repairs as needed. On the water side, the Drinking Water page says property owners are responsible for maintaining and repairing the service line from the meter to the home or business.

Redmond gets about 60 percent of its drinking water from the Tolt River Watershed through Cascade Water Alliance and pumps about 40 percent from its own aquifer. Its service line inventory found no lead service lines in the city.

If you have an irrigation system, a fire sprinkler system, a boiler, a pool or a spa, you may have a backflow assembly. Redmond says annual testing is mandatory for all water users who own a backflow assembly, regardless of how often it is used, and the city mails yearly reminders. Any state-certified backflow assembly tester can do the test.

Washington requires anyone doing plumbing for pay to hold a state plumbing certificate, and contractors must be licensed with the Department of Labor and Industries. Search the company in the L&I Verify tool. King County's hiring guidance also notes that contractors must post a bond and carry general liability insurance, which the L&I record shows. Because Redmond requires a permit even for many fixture replacements, ask every bidder whether the price includes the permit and inspection. Our hiring guide and cost guide help you compare.

This site is an independent homeowner guide. We are not a contractor, hold no license and do not perform plumbing work. To reach a plumber, call one of the licensed contractors listed on this page or see all listed contractors. If you prefer, email us your Redmond ZIP code, what is happening and a few photos. We reply by email with practical next steps. Please run the license checks above on anyone you hire, including the contractors listed on this page.