Plumbing Permit: A permit issued by a local building department authorizing the installation, alteration, or repair of plumbing systems — including drain, waste, vent, and supply lines — required before most plumbing work beyond simple fixture replacement can begin.
When a Plumbing Permit Is Required
Plumbing permits are required for: adding a new plumbing fixture location, relocating existing fixtures (moving a toilet, sink, or shower to a new location), replacing water heaters or recirculation systems, installing new water or drain lines, adding a bathroom or kitchen to a structure, installing an irrigation backflow preventer, and most other work on the drain-waste-vent (DWV) or supply systems.
Like-for-like fixture replacements — swapping a toilet for another toilet, replacing a faucet — typically do not require a permit if no DWV or supply work is involved.
Who Can Pull a Plumbing Permit
In most states, plumbing permits must be pulled by a licensed plumber. Licensed plumbers are personally responsible for the code compliance of their permitted work. Some states allow homeowners to pull plumbing permits for their own primary residence. Note that even where homeowners can pull the permit, they're still held to code compliance standards.
Plumbing Inspection Stages
Plumbing inspections typically include: a rough-in inspection before walls are closed (verifying DWV installation, pipe sizing, and system pressure testing) and a final inspection after fixtures are installed. Pressure tests — filling the DWV system with water or air to check for leaks — are commonly required at rough-in. Underground plumbing may require a separate inspection before the trench is backfilled.
Water Heater Permits
Water heater replacements almost universally require plumbing permits, even though the fixture is being replaced in-kind. Water heaters also require seismic strapping in California and other seismically active areas. The permit and inspection ensure the unit is properly vented, temperature-pressure relief valves are correctly installed, and the installation meets current code.