Drainlayer self-certification NZ: endorsement, CoC and as-builts

What changed on 7 September 2026

The Building and Construction Sector (Self-certification by Plumbers and Drainlayers) Amendment Act 2026 received Royal Assent on 2 June 2026, with supporting regulations starting on 7 July 2026, and the scheme itself went live on 7 September 2026. It is voluntary at both ends. A certifying drainlayer (or plumber) applies to the Plumbers, Gasfitters and Drainlayers Board (PGDB) for a self-certification endorsement, and the building owner chooses whether eligible work is self-certified or left to council inspection. Where it is used, the endorsed practitioner takes responsibility for certifying that the work complies with the building consent; the council does not share that liability for self-certified work. It does not remove the need for a building consent, compliance with the Building Code, or the Code Compliance Certificate (CCC).

Which drainage qualifies

MBIE’s guidance sets the tests. The work must need a building consent (exempt work is not eligible, because exempt work is not inspected anyway), and it must be on a qualifying building. It must also be designed to an Acceptable Solution or Verification Method, with a narrow exception for on-site systems that have none. The building consent itself has to identify the work as self-certifiable, and the owner must tell the council which endorsed drainlayer will carry it out.

• Building: three storeys or less, and no apartments.
• Design: to an applicable Acceptable Solution or Verification Method, such as G13/AS1, G13/AS2 or G13/AS3, G13/VM1 or VM4, or G14/VM1.
• Excluded: plumbing penetrating fire separations, plumbing in a common wall, alternative solutions (other than qualifying on-site systems), and civil works that are part of the public network.
• Mixed consents: one consent can hold both self-certifiable work and work the council still inspects.

What the Certificate of Compliance must contain

The CoC is made in the form the PGDB prescribes, and in practice it is an online form that issues the certificate once completed. MBIE lists the content: where the work was done, what was completed, the building consent number, when the work started and finished, and any supporting documents that show it complies with the consent. It names the endorsed drainlayer and their registration, confirms they are approved to self-certify and that they did or supervised the work, and lists anyone else who helped. It then states that tests were carried out at the required stages, that the results show the work performs as required, that the work complies with the consent and that all required information is included, followed by a dated signature. The supporting documents are photographs of the work, the test details and results, and as-built plans if the work differs from the consent (or an explanation of the differences).

The 10-working-day clock and the CCC

The endorsed practitioner must give the certificate of compliance to the building owner, the council and the Board within 10 working days of completing the work. The CoC is not a substitute for the CCC: the owner still applies for it, and the CoC and supporting documents must accompany that application for any self-certified work. The council must accept a valid CoC as establishing that the self-certified work complies with the consent, and it checks completeness and that your endorsement was current when the work was finished. Two practical points follow. If you supervised the work rather than doing it, you must attend site and inspect it in person before certifying; photos and third-party reports are not enough. And a single end-of-job inspection will not do where drain runs are concealed at different stages, so the certification has to be built from checks made as each stage was open to see.

Work that still goes the traditional way

If you are not endorsed, the owner does not opt in, or the drain falls outside the eligible work, the council inspects as before. The inspections verify consented drainage, and councils typically want an as-built drainage plan before they issue the CCC, so check the requirements of your council early. A fail on an inspection should be fixed and rebooked before you backfill. Connection to the public wastewater or stormwater network is a separate approval from the council or whichever water services provider runs the network where you work; confirm who approves connections locally, and get it before connecting. On-site wastewater (septic or soakage) usually also needs regional council consent under the Resource Management Act, so ask early rather than after the tank is delivered.

Trenches and the notifiable work rule

Deep trenching has its own paperwork. WorkSafe treats work in a pit, trench or excavation where a person works in a space more than 1.5 metres deep, and deeper than it is wide at the top, as notifiable work, and its guidance is that notice must be given at least 24 hours before the work starts. Emergency work after a storm or slip is treated differently. WorkSafe’s notification pages have been revised over the years, so check the current form and rule before relying on this summary. Our notifiable work page sets out the wider picture.

Keeping the drainage record in Toolie

Toolie’s drainlayer pack has an as-built drainage register. For each job you record the consent number and council, every run (from, to, wastewater or stormwater, length, diameter, material, grade and depths), offsets from fixed points so the drain can be found again, council inspections with their results, the CCTV survey and the date the as-built went to council. The register totals the drain laid by diameter and flags a foul-water run flatter than the flattest gradient listed in G13/AS2 Table 2 for its size, while reminding you to confirm the minimum for the actual discharge loading. It warns when the latest council inspection is a fail. Tick ‘self-certifying’ and enter the completion date and it counts 10 working days, skipping weekends, national public holidays and 25 December to 2 January, though regional anniversary days are not excluded. A separate self-certified work record tracks the CoC number, supporting documents and the dates sent to the PGDB, owner and council. Toolie can print a CoC draft, but the Board prescribes the form and the certificate is issued through its own system, so treat the printout as a working copy and check it against the official form.

Sources

Official sources this guide relies on. Rules change, so check the current version before relying on a date or threshold.

• MBIE: Self-certification for plumbing and drainlaying scheme, guidance (September 2026)
• MBIE Building Performance: Self-certification for plumbing and drainlaying scheme commences on 7 September 2026
• MBIE Building Performance: Certificates of compliance for self-certified plumbing and drainlaying
• Plumbers, Gasfitters, and Drainlayers Board (PGDB)
• WorkSafe: Particular hazardous work (notifiable work)
• Interpretation Act 2019, section 13 (working day)

Related: foul water drainage (G13) · stormwater drainage · building consent tracker · producer statements · invoicing. Back to drainlayers software · software for every trade.