Yes, a drainlayer can legally sign off their own work in New Zealand — but only if they hold a Certifying Drainlayer licence. This is an important distinction that many homeowners don't realise, and getting it wrong can cause serious problems when it comes time to sell your property or make an insurance claim.
The Two Levels of Drainlayer Licence in NZ
Drainlaying is restricted work in New Zealand, regulated by the Plumbers, Gasfitters and Drainlayers Board (PGDB). There are two main licence classes relevant here:
- Registered Drainlayer — Qualified and licensed to carry out drainage work, but cannot certify (sign off) their own work. They must have a Certifying Drainlayer inspect and certify the job.
- Certifying Drainlayer — Holds a higher-level licence that allows them to both carry out and certify drainage work. They can issue a Certificate of Compliance (CoC) for work they have completed.
Think of it like the difference between a builder and a Licensed Building Practitioner who can sign off restricted building work — the certifying level carries extra responsibility and accountability.
What Is a Certificate of Compliance?
A Certificate of Compliance (CoC) is the legal document that confirms drainage work has been completed to the required standard under the Plumbers, Gasfitters, and Drainlayers Act 2006. It must be issued by a Certifying Drainlayer and is required for virtually all sanitary drainage work — including new drains, alterations, and connections to the public sewer or stormwater system.
Without a CoC, your drainage work is not legally signed off, regardless of how well it was installed. This can affect:
- Building consent sign-off from your local council
- Your property's LIM report
- Insurance cover if something goes wrong
- Your ability to sell the property
Does Drain Work Need a Building Consent?
This depends on the scope of work. Some minor drainage work may fall under Schedule 1 exemptions of the Building Act 2004, meaning a building consent isn't required — but a CoC from a Certifying Drainlayer is still needed regardless. More significant work, such as installing new sanitary drains or making connections to the public network, will generally require a building consent from your local council.
Always check with your local council before starting any drainage work to confirm whether a consent is required. Requirements can vary between territorial authorities, and the rules around what's exempt are not always straightforward.
You can find general guidance on the NZ Building Code and consent requirements at MBIE Building Performance.
Can a Homeowner Do Their Own Drainlaying?
Generally, no. Drainlaying is restricted work under NZ law, which means it must be carried out by (or under the direct supervision of) a licensed drainlayer. Unlike some electrical work where owner-occupiers have limited DIY rights, there is no equivalent homeowner exemption for drainlaying.
Attempting to carry out your own drainage work without a licence is illegal and can result in fines. More importantly, uncertified drain work poses real health and environmental risks — faulty sanitary drainage can contaminate groundwater and create serious public health hazards.
Safety note: Never work in or around existing drains without understanding the risks of confined spaces and exposure to sewage. If you suspect a drain is blocked or damaged, contact a licensed drainlayer rather than attempting repairs yourself.
How to Check a Drainlayer's Licence
Before hiring anyone to carry out drainage work, it's worth confirming their licence status. The PGDB maintains a public register where you can search for licensed practitioners and check whether they hold a Certifying Drainlayer licence. This takes only a few minutes and gives you peace of mind.
Key questions to ask your drainlayer:
- Are you a Certifying Drainlayer?
- Will you be issuing a Certificate of Compliance for this work?
- Is a building consent required for this job, and will you help manage that process?
When to Call a Professional
You should engage a Certifying Drainlayer for any of the following:
- New sanitary drain installations (toilets, bathrooms, kitchens)
- Connecting to the public sewer or stormwater network
- Relocating or altering existing drains
- Replacing damaged or collapsed drain pipes
- Any work that requires a building consent or CoC
A good drainlayer will be upfront about what's required, handle the paperwork, and ensure the work is inspected and certified correctly. You can find qualified, local drainlayers on tradedirectory.co.nz.
Certifying Drainlayer
