Do Plumbing Plans include gas lines?

Yes — when your ADU design uses gas appliances, our plumbing plans include the gas piping plan with sizing, shutoff valves, and sediment traps. If the design is all-electric, there is no gas line to draw, and we coordinate the electric alternative across your mechanical and electrical sheets instead.

What the gas portion shows

• Pipe sizing for aggregate demand. The piping is sized to deliver the combined BTU/hr load of every gas appliance running at once while holding adequate pressure (commonly about 7 inches water column for standard residential appliances), based on total connected load, developed pipe length, and material.
• A manual shutoff valve at each appliance, accessible and within sight of the unit.
• A sediment trap (drip leg) ahead of each appliance gas valve to catch moisture and debris before it reaches the burner controls.
• Routing and connection points from the meter/branch to each appliance, with notes for the required pressure (leak) test before concealment.

Common ADU gas loads

If gas is used, the typical appliances are a tankless or tank water heater, a furnace or wall heater, a range/cooktop, and occasionally a gas dryer. Each adds to the BTU total the line must carry. Many California homeowners now go all-electric — a heat-pump water heater and heat-pump HVAC — which removes the gas line entirely and is often the cheaper, faster path, especially in cities with all-electric ordinances.

What is on you vs. on the utility

1. On the plans / your plumber: the piping layout, sizing, shutoffs, sediment traps, and pressure test shown on our sheets.
2. On the gas utility (SoCalGas, PG&E, Southwest Gas): the meter and service connection. Added ADU load may require a meter upgrade or relocation — a separate application with its own timeline and fees, so start that early.

All-electric ordinances, gas-infrastructure cost rules, and meter requirements vary by city and utility and continue to change — confirm current requirements with your local building department and gas provider.

Whether your project is mixed-fuel or all-electric, our plumbing plans reflect the right approach, and the Full MEP package keeps gas, mechanical, and electrical decisions consistent. Start your order when you are ready.