Accepting a drainlayer quote without reading the fine print can lead to unexpected costs, delays, and disputes. A well-written quote gives you a clear picture of the work involved, the materials being used, who is doing the job, and what happens if things don't go to plan. Here's what to look for before you say yes.
Full Scope of Work
The most important part of any quote is a clear, written description of exactly what work will be carried out. Vague language like "drainage works" isn't good enough. A detailed quote should specify:
- Whether the work involves stormwater drains, wastewater drains, or both
- The location of the drain runs (e.g., from the house to the boundary trap, or from the boundary to the council connection)
- Pipe sizes and materials (e.g., 100 mm uPVC to AS/NZS 1260)
- Depth of excavation and any shoring or safety measures required
- Reinstatement — will the tradesperson restore your lawn, driveway, or concrete after the dig?
- Any inspection chambers, gully traps, or vent stacks being installed or replaced
If the quote is silent on any of these points, ask the drainlayer to clarify in writing before you accept.
Licensing and Compliance Details
Drainlaying is restricted work under the Plumbers, Gasfitters, and Drainlayers Act 2006. Only a person who holds a current licence issued by the Plumbers Gasfitters & Drainlayers Board (PGDB) may carry out, supervise, or certify drainlaying work in New Zealand. This applies to both sanitary drains and stormwater drains connected to a public system.
Your quote should include:
- The name and PGDB licence number of the licensed drainlayer responsible for the work
- Confirmation that a Certificate of Compliance (CoC) will be issued on completion
- Details of any subcontractors and confirmation they are also licensed
You can verify a licence on the PGDB website before accepting the quote.
Building Consent and Council Requirements
Many drainlaying jobs require a building consent from your local council, particularly for new drain connections, major alterations, or work on public drains. Some minor repairs may be exempt under Schedule 1 of the Building Act 2004 — but always confirm this with your council before assuming no consent is needed.
The quote should state:
- Whether a building consent is required and who will apply for it
- Any council inspection fees or connection fees that apply
- Who is responsible for arranging council inspections during and after the work
For guidance on the NZ Building Code requirements relevant to drainage (particularly Clause G13 – Foul Water and Clause E1 – Surface Water), visit MBIE Building Performance.
Itemised Pricing
A trustworthy quote breaks costs down so you can see where your money is going. Look for:
| Item | What to Check |
|---|---|
| Labour | Hours or day rates, number of workers |
| Materials | Pipe, fittings, chambers — brand and spec |
| Plant & equipment | Excavator hire, traffic management if needed |
| Consent & inspection fees | Clearly listed, not buried in a lump sum |
| Reinstatement | Concrete, asphalt, topsoil, turf |
| GST | Confirm whether pricing is GST-inclusive or exclusive |
As a broad guide, drainlaying costs in NZ vary significantly depending on depth, ground conditions, location, and access — always get at least two or three quotes to compare.
Provisional Sums and Variations
Drainlaying often uncovers surprises underground — old pipes, rock, or unexpected services. A good quote will include a provisional sum for unforeseen conditions and explain the process for agreeing on variations before extra work proceeds. Make sure the quote states that you will be notified and must approve any additional costs in writing before they are incurred.
Timeline and Programme
The quote should give you a realistic start date and estimated completion time. If the job requires a council inspection at a specific stage (e.g., before backfilling), the programme should account for that wait time. Ask what happens if the job runs over schedule and whether there are any penalty or delay clauses.
Warranties and Defects Period
Ask whether the quote includes a workmanship warranty and for how long. Materials may also carry a manufacturer's warranty. The BRANZ Good Practice Guide for drainage is a useful reference for understanding what quality workmanship looks like.
Insurance
Confirm the drainlayer holds current public liability insurance and, if they have employees, employer's liability cover. A reputable tradesperson will have no hesitation providing proof of this.
When to Call a Professional
All drainlaying connected to a sanitary or stormwater system must be carried out by a licensed drainlayer — this is not optional. Homeowners are not permitted to carry out this work themselves (with very limited exceptions for minor repairs on their own property — check with the PGDB if you are unsure). Attempting unlicensed drainlaying can result in fines, failed inspections, and costly remediation. Find a qualified local drainlayer on tradedirectory.co.nz.
Safety note: Excavations beyond a certain depth require specific safety measures under WorkSafe NZ guidelines — check current WorkSafe requirements for the applicable threshold. Never enter an unshored trench.
Sources & Further Reading
- Plumbers Gasfitters & Drainlayers Board – Licence verification
- MBIE Building Performance – Building Code and consents
- BRANZ – Building research and good practice guides
- WorkSafe NZ – Excavation safety
- Consumer NZ – Getting quotes and contracts
- Licensed Building Practitioners – Understanding restricted building work
Certifying Drainlayer
