In New Zealand, plumbing, gasfitting, and drainlaying are restricted trades — meaning the law sets strict rules about who can legally carry out this work. The short answer is: no, a licensed plumber cannot lawfully subcontract restricted plumbing work to an unlicensed person. Here's what you need to know as a homeowner.
What Makes Plumbing a Restricted Trade?
Under the Plumbers, Gasfitters, and Drainlayers Act 2006, certain work is classified as restricted and can only be performed by someone who holds the appropriate licence or is working under direct supervision as a registered trainee. The Plumbers, Gasfitters and Drainlayers Board (PGDB) is the regulatory body responsible for licensing, investigating complaints, and taking disciplinary action against those who break the rules.
Restricted work includes:
- Installing, altering, or repairing sanitary plumbing (toilets, sinks, showers, baths)
- Connecting to or modifying the water supply system
- Drainlaying — laying or altering underground drainage
- Gasfitting — installing or modifying gas appliances and pipework
Can a Licensed Plumber Subcontract to an Unlicensed Person?
No — not for restricted work. A licensed plumber may use unlicensed labourers for non-restricted tasks (such as digging trenches or general labouring), but any work that falls within the definition of restricted plumbing or drainlaying must be carried out by a licensed or supervised registered tradesperson.
If a licensed plumber subcontracts restricted work to an unlicensed individual, both parties may be breaking the law. Penalties under the Act can include fines and loss of licence for the licensed tradesperson, and fines for the unlicensed person performing the work.
What About Trainees and Apprentices?
Registered trainees can legally perform restricted work, but only under the direct supervision of a licensed tradesperson. "Direct supervision" has a specific legal meaning — the supervisor must be on-site and actively overseeing the work, not simply available by phone. If a trainee is left to work alone on restricted tasks, that arrangement is unlawful.
Why Does This Matter for Homeowners?
As a homeowner, you may not always know who is actually doing the work on your property. Here's why it matters:
- Insurance and liability: If unlicensed work causes damage — a burst pipe, a gas leak, or a sewage backup — your home insurance may decline the claim because the work wasn't done legally.
- Building consent and compliance: Plumbing work that requires a building consent must be signed off by a licensed tradesperson. Work done by an unlicensed person cannot be legally certified.
- Safety: Faulty plumbing and gasfitting can cause serious harm, including flooding, contamination of drinking water, or gas explosions. The licensing system exists to protect you.
- Resale issues: Unconsented or non-compliant plumbing work can create significant problems when you sell your home.
The MBIE Building Performance website has useful guidance on what work requires a building consent and what falls under Schedule 1 exemptions — though you should always confirm with your local council, as requirements can vary.
How to Check Your Plumber Is Licensed
Before any work begins, ask your plumber for their licence number and check it on the PGDB's online register. This is free and takes only a minute. A legitimate tradesperson will have no hesitation providing this information.
Also ask:
- Will all restricted work be carried out by a licensed person?
- If subcontractors are used, are they also licensed?
- Will the work be inspected and signed off with a Certificate of Compliance?
| What to Check | Why It Matters |
|---|---|
| PGDB licence number | Confirms the tradesperson is legally authorised |
| Certificate of Compliance | Legal proof the work meets NZ standards |
| Building consent (if required) | Ensures council sign-off for notifiable work |
| Subcontractor licences | Confirms everyone on-site is legally qualified |
What Homeowners Can Do Themselves
The law does allow homeowners to carry out some minor plumbing tasks on their own home without a licence — such as replacing tap washers or a showerhead. However, anything involving connections to the water supply, drainage, or gas is restricted work and must be done by a licensed tradesperson. If in doubt, contact the PGDB or your local council before attempting any DIY plumbing.
When to Call a Professional
Always use a licensed plumber, gasfitter, or drainlayer for any restricted work. If you suspect work on your property has been carried out by an unlicensed person, contact the PGDB to report it and seek advice. You may also want to consult Consumer NZ if you've paid for work that wasn't done legally.
You can find qualified, licensed plumbers in your area right here on tradedirectory.co.nz — giving you confidence that the person turning up to your home holds the right credentials.
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