Planning the Plumbing for a New Home in Green

Decisions That Belong on the Drawings

Builders' plans show where fixtures go, but they rarely show how water gets to them or how waste leaves. Thinking that through early heads off problems such as a toilet sitting on top of a beam, a drain with nowhere to go, or a long wait for hot water at the far bathroom. A few minutes of plumbing input at the design stage can save real money once construction starts.

• Stack bathrooms and the laundry over each other or back to back where possible
• Keep wet walls away from exterior walls in a cold climate
• Leave room in floor framing for drains to run with proper slope
• Choose fixtures early so rough-in dimensions are known
• Decide on extras now: ice maker, pot filler, utility sink, outdoor kitchen

Manifold or Trunk-and-Branch Supply?

In a trunk-and-branch system, a main supply line runs through the house with smaller branches teed off to each fixture group. It uses less pipe and is familiar to every plumber. In a home-run manifold system, each fixture gets its own PEX line from a central manifold with individual shutoffs.

Manifolds make it easy to shut off one fixture without affecting the rest of the house, reduce pressure swings when several fixtures run at once and have fewer hidden fittings. They use more tubing and need a good spot for the manifold. Many new houses use a hybrid. We lay out the options for your floor plan and recommend what makes sense.

Where the Water Heater Goes Matters

Water heaters often end up in a basement corner simply because that is where the gas line and the water service come in. If the primary bath is two floors up and on the opposite side of the house, that location means a long wait for hot water every morning. Options include moving the heater closer to the main bathrooms, adding a recirculation loop or using smaller pipe on long hot runs so hot water arrives sooner.

We also plan for venting, combustion air, a drain pan where needed and a floor drain nearby.

Rough-Ins for What You Might Add Later

Not every space gets finished right away. Adding stub-outs during construction costs far less than breaking concrete later. Common future-proofing rough-ins include:

• A full basement bathroom with drains in the slab and a vent stubbed up
• A wet bar or kitchenette in the lower level
• A utility sink or floor drain in the garage
• Capped supply lines for a future outdoor kitchen or irrigation

How We Work With Your Builder

After a free estimate and your approval of the plumbing specifications, we schedule the underground work before the slab or basement floor is poured, return for rough-in once framing is done and finish after drywall and cabinets are in place. Each stage is tested and inspected before it is covered. For contractor-managed builds, our construction plumbing services cover scheduling with general contractors, and when it is time to set fixtures and appliances, see our installation services. The new plumbing overview covers materials in more detail.