Tearing out a bathroom is a satisfying renovation milestone, but getting the plumbing disconnection right is critical — both for safety and to stay on the right side of New Zealand law. Some steps are perfectly fine for a capable homeowner to handle, while others are restricted plumbing work that must be carried out by a licensed tradesperson. Here's how to approach it safely and legally.
Understand What Is Restricted Work
In New Zealand, plumbing and drainlaying work is regulated under the Plumbers, Gasfitters, and Drainlayers Act 2006. Restricted work includes connecting or disconnecting sanitary plumbing (toilets, waste pipes, drain connections) and any work on the water supply system beyond simple isolation. Only a licensed plumber or drainlayer may legally carry out this work.
Before you pick up a spanner, check the Plumbers Gasfitters & Drainlayers Board website to understand what is and isn't permitted for homeowners. Getting this wrong can void your home insurance and create issues when you sell.
Step 1 — Check Whether You Need a Building Consent
Removing a bathroom may or may not require a building consent, depending on the scope of work. Under Schedule 1 of the Building Act 2004, some minor work is exempt, but structural changes, relocating plumbing, or altering drainage almost always require consent. Always confirm with your local council before starting. You can find general guidance at MBIE Building Performance.
Step 2 — Turn Off the Water Supply
This is the first practical step and something most homeowners can do themselves.
- Locate the isolation valves under the basin and toilet cistern — these are small quarter-turn valves on the supply pipes. Turn them clockwise to close.
- If there are no isolation valves (common in older NZ homes), you'll need to turn off the toby (water meter valve) at the boundary. This cuts water to the whole house.
- Open taps in the bathroom to release pressure and drain remaining water from the pipes.
- Safety note: Never work on pressurised water lines. Always confirm the supply is off before cutting or disconnecting anything.
Step 3 — What a Homeowner Can Typically Do
Once the water is isolated, there are some tasks you can reasonably handle yourself:
- Removing the toilet cistern lid and emptying the cistern by flushing and sponging out remaining water.
- Disconnecting the flexible braided hoses that connect the cistern and basin taps to the isolation valves (once the water is off). These are push-fit or compression fittings and don't require a licence to remove.
- Removing tapware from the basin or bath once supply lines are disconnected.
- Lifting the toilet pan off the floor after the cistern is removed — the pan is typically bolted or siliconed down. The soil pipe connection beneath, however, must be properly capped by a licensed plumber.
- Removing the vanity cabinet once the basin and plumbing connections are clear.
Step 4 — What Must Be Done by a Licensed Plumber
The following tasks are restricted work and must be completed by a licensed plumber or drainlayer:
- Capping or modifying the soil pipe (the large-diameter waste pipe the toilet connects to).
- Disconnecting or capping waste pipes from the shower, bath, or basin that connect into the sanitary drainage system.
- Any work on the hot water system, including disconnecting supply lines at the cylinder or manifold.
- Relocating or removing drain connections — this is drainlaying work and requires a licensed drainlayer.
- Pressure-testing or certifying the plumbing after the renovation is complete.
A licensed plumber will also issue a Certificate of Compliance (CoC) for the work, which is important for your building consent sign-off and future property sales.
Step 5 — Dealing with the Shower and Bath Waste
Shower traps and bath wastes connect into the drainage system. While you can remove the shower tray or bath itself once the waste is disconnected, the actual disconnection from the drain must be done by a licensed plumber or drainlayer. Ensure the drain opening is temporarily capped to prevent sewer gases from entering the house during demolition.
Step 6 — Prepare for Demolition
Once all plumbing is properly isolated and capped by your plumber:
- Take photos of pipe locations before removing wall linings — this helps when reinstating.
- Check whether wall linings contain asbestos (common in NZ homes built before the mid-1980s). If in doubt, have the material tested before demolition. WorkSafe NZ has guidance on managing asbestos safely.
- Protect the floor and adjacent areas from debris.
- Ensure adequate ventilation throughout the work.
When to Call a Professional
For the restricted plumbing work described above, you must engage a licensed plumber and/or drainlayer. Even for the DIY-friendly steps, if you're unsure at any point, stop and get professional advice. A good plumber can often disconnect everything in a few hours, giving you a clean, safe starting point for your demolition.
You can find qualified, local demolition contractors and licensed plumbers in your area at tradedirectory.co.nz.
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