Replacing a laundry sink tap might seem like a straightforward weekend job, but in New Zealand the rules around plumbing work are stricter than many homeowners realise. Whether you can legally do it yourself depends on exactly what the job involves — and getting it wrong can void your home insurance or create compliance headaches down the track.
What the Law Says About Plumbing Work in NZ
Under the Plumbers, Gasfitters, and Drainlayers Act 2006, most plumbing work on a sanitary plumbing system is restricted work that must be carried out (or supervised) by a licensed tradesperson. The Plumbers, Gasfitters and Drainlayers Board (PGDB) is the authority that licenses and regulates these tradespeople in New Zealand.
The key question is: does your tap job involve work on the sanitary plumbing system (the pipes that carry water to and from fixtures), or is it simply swapping out a fitting that's already connected?
What a Homeowner Can Generally Do
As a homeowner, you are generally permitted to carry out like-for-like replacement of tapware where:
- You are replacing an existing tap with a new tap of the same type and configuration
- The supply pipes and connections are not being altered — you're simply unscrewing the old tap and screwing on the new one
- No new pipework is being run or modified
- The work is on your own home (not a rental or commercial property)
For example, if your laundry tub has a pair of quarter-turn pillar taps and you want to swap them for a new pair of pillar taps using the existing flexi-hose connections, this is generally considered minor maintenance that a competent homeowner can tackle.
Important: Even where DIY is permitted, the work must still comply with the NZ Building Code and relevant standards. Always turn off the water at the toby (street valve) or isolation valve before starting.
What Is Restricted Plumbing Work
The following tasks must be done by a licensed plumber — attempting them yourself is illegal and could result in fines or insurance issues:
- Installing new pipework or extending existing supply lines
- Relocating a tap to a new position
- Connecting to or modifying the sanitary drain (the waste pipe from the sink)
- Installing a new laundry tub from scratch, including waste connections
- Any work involving hot water supply pipes beyond a simple tap swap
- Work in rental properties — landlords must use licensed tradespeople for plumbing under the Healthy Homes Standards
If you're unsure whether your specific job crosses into restricted territory, contact the PGDB or a licensed plumber before you start.
Step-by-Step: Simple Tap Replacement (DIY)
If your job is a straightforward like-for-like swap, here's the general process:
- Turn off the water supply at the isolation valve under the tub or at the toby outside.
- Open the old tap to release pressure and drain residual water.
- Disconnect the flexi-hoses from the tap tail using an adjustable spanner — have a towel handy.
- Remove the old tap — undo the back nut beneath the sink deck.
- Fit the new tap, following the manufacturer's instructions. Use thread tape (PTFE tape) on threaded connections.
- Reconnect the flexi-hoses and hand-tighten, then snug up with a spanner — don't overtighten.
- Turn the water back on slowly and check for leaks.
Tools You'll Need
- Adjustable spanner or basin wrench
- PTFE thread tape
- Towels or a small bucket
- Torch
You'll find tapware and fittings at Bunnings, Mitre 10, or PlaceMakers. Choose tapware that suits your existing hole size (check your existing tap hole size and spacing before purchasing replacement tapware).
Does This Work Need a Building Consent?
Simple like-for-like tap replacement is generally exempt from building consent under Schedule 1 of the Building Act 2004. However, if you're installing a new tub or modifying pipework, consent may be required. Always check with your local council to confirm — rules can vary and it's your responsibility to comply. More guidance is available from MBIE Building Performance.
Safety Note
Always isolate the water supply before starting any tap work. If you discover corroded pipes, signs of water damage, or anything unexpected behind the wall or under the tub, stop and call a licensed plumber. Pushing on with damaged pipework can cause serious water damage to your home. If you are not confident, stop and call a licensed plumber.
When to Call a Professional
Call a licensed plumber if:
- The job involves any new pipework, drain connections, or relocating the tap
- You're working on a rental property
- You discover corroded or damaged pipes during the job
- You're not confident in your DIY ability — a small mistake can cause significant water damage
- The tap is connected to a continuous flow or hot water cylinder system
A qualified plumber will also issue you a Certificate of Compliance for restricted work, which is important for insurance and future property sales. You can find licensed local plumbers on tradedirectory.co.nz.
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