Plumbing Stages in a New Build: Underground, Rough-In and Fit-Off

Construction plumbing happens in stages, and each stage needs to be coordinated with the builder and other trades. Understanding the sequence helps explain why plumbing decisions need to be made well before the fixtures are installed.

For more detail on the service itself, see our construction plumbing page.

Underground plumbing

Before slabs and finished surfaces are completed, sewer, drainage and water services may need to be installed below ground. Accuracy is critical because these services become difficult to alter later.

Slab and pre-pour work

Where plumbing passes through or below a slab, the set-out must match the building plans. Fixture locations and penetrations need to be confirmed before the concrete stage.

Rough-in plumbing

During rough-in, water, waste and other services are run through walls, floors and ceilings before linings are completed.

Fit-off

Fit-off is when toilets, taps, basins, sinks, showers and other fixtures are installed and connected after the building has progressed to the appropriate stage.

External and final connections

Depending on the project, final work may include hot water systems, external taps, rainwater, sewer connections and other site services.

Testing and handover

Plumbing should be tested at the relevant stages and checked again when the system is complete. Problems are easier to fix before finishes and handover.

Coordination is the key

A good construction plumbing program follows the build schedule and makes sure fixtures, plans and service requirements are available before each stage begins.

Related plumbing services

You may also find these related service pages useful: construction plumbing, underground plumbing, rough-in plumbing.

Need help with this type of plumbing?

If you are planning this work or dealing with a problem now, see our construction plumbing service page for the relevant plumbing options and next steps.