DIY plumbing in NZ: what you can — and can’t — legally do

Why this matters

Doing small plumbing jobs yourself can save time and money, but getting the boundaries wrong can create health and safety risks, damage your property and leave you non-compliant with New Zealand rules. This guide explains what homeowners in Wellington and surrounding suburbs can reasonably tackle and when you must call a licensed professional.

Quick checklist: when DIY is OK

For many simple, non-restricted tasks you can do the work yourself — but always isolate water and follow safe practices. Typical DIY jobs include:

• Replacing tap washers and cartridges (basic tap repairs)
• Changing showerheads and hoses
• Clearing minor blockages with a plunger or hand snake
• Replacing flexible supply hoses under sinks (if just replacing like-for-like and isolating supply)
• Cleaning strainers and trap baskets
• Shutting off mains and isolating valves during an emergency

These tasks are usually low risk and do not change the plumbing system’s layout or connections to the public network.

What you must not do yourself (restricted or high-risk work)

Many types of plumbing, drainage and gas work are legally restricted in New Zealand and must be done by a registered/licensed tradesperson. Examples you should not attempt on your own:

• Installing, relocating or altering sanitary plumbing and drainage (wastewater sewer connections or new drainage lines)
• Connecting to or modifying the public sewer or stormwater network
• Installing or modifying water mains or property connections to mains water
• Gasfitting work (installing or altering gas appliances, lines, cylinders) — gas requires a licensed gasfitter
• Installing or altering hot-water cylinders where gas or electrical connections are involved — electrical and gas connections must be done by qualified trades
• Installing backflow prevention devices or anything that affects potable water safety unless you are certified
• Work that requires excavation or affects structural building fabric (you may need building consent or a specialist)

Restricted work must be carried out by people registered under New Zealand’s plumbing and gas regulations (check the Plumbers, Gasfitters & Drainlayers Board register).

Safety first: risks to be aware of

Even seemingly small mistakes can have serious consequences:

• Incorrect wastewater connections can cause sewage leaks and contamination.
• Poorly installed gas fittings risk leaks, fire, explosions and carbon monoxide poisoning.
• Improper backflow protection can contaminate your drinking water supply.
• Wrong electrical connections to hot-water units risk shock and fire — call a licensed electrician.

If you smell gas, suspect a major leak, or see sewage on your property, turn off the service (if safe to do so), evacuate the area and call an emergency licensed tradesperson immediately.

Permits, council rules and compliance (Wellington context)

Work that affects the public network, structural elements or safety systems often requires council approval or a building consent. In Wellington and the wider region (including Lower Hutt and Porirua), councils expect:

• Authorised contractors for sewer or stormwater connections to the public network
• Evidence that restricted work was completed by a registered tradesperson
• Documentation for any alterations that affect building code compliance

Before starting any work that alters drainage, mains connections, gas lines or hot water systems, check with your local council (for example Wellington City Council) to confirm whether a permit or consent is required.

How to find the right local help in Wellington and suburbs

When you need a professional, choose a licensed plumber/drainlayer/gasfitter who:

• Is registered with the Plumbers, Gasfitters & Drainlayers Board (PGDB) — you can check registration online
• Has experience with council requirements in Wellington, Johnsonville, Karori, Newtown, Island Bay, Lower Hutt and Porirua
• Provides written quotes, scope of work and evidence of compliance on completion
• Is prepared to pull permits or liaise with the council when necessary

Local businesses can help ensure work is done safely and in accordance with New Zealand rules. For example, local Wellington-area plumbing businesses can advise on consent requirements and carry out restricted plumbing, drainage and gasfitting work professionally.

Record keeping and warranties

After any work on your home, keep:

• Receipts and invoices
• Copies of compliance certificates or contractor registration details
• Any council approvals or producer statements

These documents are important when selling your property or if problems appear later.

Practical tips for Wellington homeowners

• Know where your water isolating valves and the mains shut-off are located.
• Label isolating valves for hot water, cold water and outdoor taps.
• Use a plunger or hand auger for simple blockages; stop and call a professional if the problem persists.
• If you live in an older Wellington house, be cautious when altering old pipework — materials and layouts can be complex.
• When in doubt, call a registered plumber — the small save you get from DIY can vanish if repairs are needed later.

Where to get more information and help

For authoritative information on local plumbing services in the Wellington region and to discuss work that must be carried out by licensed tradespeople, you can visit Accrete Plumbing’s site: https://www.accreteplumbing.co.nz/. Their team can advise on compliance issues, restricted work and emergency repairs in Wellington and surrounding suburbs.

Also check the Plumbers, Gasfitters & Drainlayers Board (PGDB) register to confirm a tradesperson’s registration before allowing restricted work.