The 2025 Washington State Plumbing Code follows the Uniform Plumbing Code with state amendments, adopted under WAC 51-56. The City of Seattle adds its own local amendments. Everett and most of Snohomish County implement the state code more or less directly. The 2025 update brought a few changes worth knowing if you’re planning work, buying a home, or just trying to understand why an inspector is asking about something that wasn’t required ten years ago.
The Biggest Changes That Affect Residential Work
Five items showing up most often on Everett-area inspections under the 2025 code.
- Water heater earthquake strapping. Required statewide. Two straps minimum, located in the upper and lower third of the tank, anchored to studs. Not new but increasingly enforced.
- Expansion tanks on closed systems. Any home with a backflow preventer or pressure-reducing valve at the main is technically a closed system and requires an expansion tank on the water heater. The 2025 code clarified the enforcement — inspectors are checking this on every water heater swap.
- T&P relief discharge piping. Must terminate within 6 inches of the floor, in an approved location, without a trap or valve in the line. A surprising number of older Everett homes have non-compliant discharge piping that gets flagged on inspection.
- Lead-free fittings. Under federal Reduction of Lead in Drinking Water Act, any fitting in contact with potable water has to meet the 0.25% lead-weighted average standard. The 2025 state code aligns enforcement.
- Water heater pan and drain. Required for water heaters located where a leak would cause damage (most interior installs). Pan must be drained to an approved location.
What Hasn’t Changed (But Still Trips People Up)
Permit requirements are largely unchanged but enforcement is stricter in 2025. Cross-connections, backflow prevention on irrigation systems, and proper vent sizing are all areas where we see existing installations flagged on remodel work. If you’re touching an existing system, the inspector can require you to bring adjacent non-compliant items up to current code — even if those items weren’t part of your project scope. Our plumbing permit requirements guide covers when permits are required, which is the precondition for inspection.
What This Means for Older Everett Homes
The 1950s–80s housing stock common in Riverside, Pinehurst, and Northwest Everett often has multiple code-current issues that weren’t problems when the home was built. Galvanized supply lines, polybutylene from the 80s–90s, undersized vents, missing T&P discharge piping, no expansion tank. None of these is a violation as long as you don’t touch the relevant system. The moment you do — replacing the water heater, repiping, remodeling the bathroom — you’re triggering compliance updates for whatever the inspector identifies in the work area.
This sounds harsh but it’s actually how building codes work for most US jurisdictions. The rationale: if we never updated existing installations, code improvements would never reach existing homes. The 2025 enforcement bump is part of a multi-year tightening across the West Coast specifically on seismic and water-quality items.
How to Approach a Compliance Update Smartly
Get a plumbing inspection scoped for code compliance before starting any major work. Our plumbing inspection checklist walks the items you can check yourself, but a licensed plumber’s eyes on the system before you commit to a remodel can save you thousands. Knowing what’ll come up at inspection lets you budget for it instead of being surprised by a $4,000 add at the end of the project.
For permitted work in Everett, our plumbing remodeling team handles code compliance as part of the project. Or reach our licensed Everett plumber directly for code questions on specific work. We know what the inspectors look for here and we’ll tell you straight whether you’re at risk.
