California Plumbing Code: Everything Homeowners Need to Know in 2025

The California Plumbing Code sets the legal standards for plumbing design, materials, installation, and safety in both residential and commercial buildings. If you’re planning a remodel, installing new plumbing, or upgrading your fixtures in Los Angeles, understanding these codes is essential to staying compliant and avoiding costly setbacks.

What Is the California Plumbing Code?

The California Plumbing Code (CPC) is a statewide set of building regulations adopted from the Uniform Plumbing Code (UPC) and customized to California’s environmental and seismic needs. It’s updated every three years by the California Building Standards Commission (CBSC) and covers water supply systems, drainage, gas piping, fixtures, backflow prevention, and graywater systems.

Why the California Plumbing Code Matters in 2025

With water conservation, safety, and sustainability at the forefront, the California Plumbing Code plays a critical role in protecting homes, infrastructure, and public health. As of the 2022–2025 cycle, changes include updated requirements for water heaters, graywater recycling, and lead-free fittings.

You can access the full CPC at the California Building Standards Commission.

Top 6 Areas Covered by the California Plumbing Code

1. Pipe Sizing & Materials: Specifies allowable materials (e.g., copper, PEX, CPVC) and sizing standards based on fixture count and water pressure needs.
2. Water Heater Installation: Mandates pressure relief valves, strapping for earthquake safety, and ventilation clearances.
3. Drainage Systems: Rules for slope, cleanouts, and venting to ensure proper wastewater removal and prevent gas backflow.
4. Backflow Prevention: Critical for safeguarding the potable water supply, especially in irrigation and commercial kitchens.
5. Graywater Systems: Encourages recycling of water from laundry and sinks for outdoor use—essential in drought-prone areas.
6. Fixture Requirements: All new fixtures must be WaterSense-labeled to meet strict flow rate limitations.

Who Needs to Follow the California Plumbing Code?

Any homeowner, contractor, or business in California performing plumbing work that exceeds simple fixture replacement must follow the California Plumbing Code. This includes:

• Bathroom or kitchen remodels
• Water heater installations
• New construction projects
• Accessory Dwelling Unit (ADU) builds
• Commercial tenant improvements

Do I Need a Permit?

In most cases, yes. Cities like Los Angeles require plumbing permits for any work involving water, gas, or waste systems. You’ll also need inspections during and after the work to ensure compliance with the California Plumbing Code.

Pro Tip: Zenon Plumbing helps homeowners and property managers navigate all permit and inspection requirements, saving you time and avoiding red tape.

Zenon Plumbing: Your California Code Experts

At Zenon Plumbing, our licensed professionals stay current with every update to the California Plumbing Code. We ensure all work meets state and local standards—whether it’s a tankless water heater installation or a full bathroom re-pipe. Schedule an appointment today for code-compliant plumbing with peace of mind.

FAQ: California Plumbing Code

How often is the California Plumbing Code updated?

Every three years. The current cycle runs from 2022–2025 and includes green building and water efficiency updates.

Can I do plumbing work without a permit?

Minor repairs like changing a faucet don’t require one, but anything affecting the system’s function or structure does.

What happens if I don’t follow the code?

You may face fines, be forced to redo the work, or experience insurance claim denials in the event of water damage or failure.

Are PEX pipes allowed in California?

Yes, PEX is code-approved and widely used for both hot and cold water lines due to its flexibility and efficiency.

Does California have low-flow requirements for toilets and faucets?

Yes. All fixtures must meet strict flow rate limits (e.g., 1.28 gallons per flush for toilets) under CALGreen and CPC mandates.

How do I find my local plumbing code requirements?

Start with the CPC, then check your city or county building department. For Los Angeles, visit LADBS.org](https://www.ladbs.org).

What’s the difference between CPC and UPC?

UPC is a model code; CPC adopts and modifies it for California’s environmental, seismic, and water conservation needs.

Conclusion: Stay Compliant with the California Plumbing Code

The California Plumbing Code exists to keep homes safe, efficient, and sustainable. Whether you’re a homeowner or contractor, understanding and following these rules helps you avoid delays, ensure quality, and protect your investment. Let Zenon Plumbing be your guide to code compliance from planning to inspection.

Book a code-compliant service today and experience expert-level work with no corners cut.