Designers and self-certification for plumbing and drainlaying

Last updated: 7 September 2026

Using an endorsed plumber or drainlayer to self-certify eligible plumbing or drainlaying can help speed up the building consent process. Find out what work can be self-certified, what information needs to be included in building consent applications, and how to coordinate effectively with endorsed plumbers and drainlayers.

What designers need to know

Owners can choose whether to have their project's plumbing and drainlaying either:

self-certified by an endorsed plumber or drainlayer, or
inspected by a building consent authority (BCA).

Building consents can have a mixture of work that have both:

self-certifiable plumbing and drainlaying
plumbing and drainlaying that follow the standard building consent inspections process.

If you design building work that includes plumbing or drainlaying, self-certification may affect how compliance is demonstrated, but not how work is designed.

Only plumbers and drainlayers endorsed by the Plumbers, Gasfitters, and Drainlayers Board can self-certify.

All plumbing and drainlaying still needs to comply with the Building Code.

Designer responsibilities

Designers must:

design work that complies with the Building Code
provide clear, accurate documentation
identify when self-certifiable plumbing or drainlaying work is part of the project
list the proposed self-certified work in the building consent application
if known, include the endorsed plumber or drainlayer’s name on the building consent application
ensure the plumbing or drainlaying work is the type of work eligible for self-certification.

The endorsed plumber or drainlayer’s name must be provided to the BCA before building work starts. 

Self-certification does not change design standards or obligations.

What plumbing and drainlaying work can be self-certified

The self-certification scheme only applies to certain types of eligible plumbing and drainlaying work.

The work must meet the eligibility requirements for the scheme, including limits on building height and design requirements.

Check what plumbing and drainlaying work can be self-certified

Confirm endorsement for a plumber or drainlayer

Only plumbers and drainlayers endorsed by the Plumbers, Gasfitters, and Drainlayers Board can self-certify.

Search the Plumbers, Gasfitters, and Drainlayers Board register to check a plumber or drainlayer’s endorsement – pgdb.co.nz

Coordination with endorsed plumbers and drainlayers

Good coordination helps avoid confusion about what can and cannot be self-certified.

If a project intends to have plumbing and drainlaying self-certified by an endorsed plumber or drainlayer:

designers should clearly show the scope of this work in the building consent application
any changes during construction should be managed carefully – endorsed plumbers and drainlayers certify their work complies with the building consent.

Managing changes

Endorsed plumbers and drainlayers still can apply for a minor variation. If the scope of the work changes, the building consent applicant must apply for a building consent amendment.

If the change means it is no longer work that can be self-certified, then it will need BCA inspections.

If an endorsed plumber or drainlayer does not want to self-certify any work listed on the building consent, the options are:

apply for a building consent amendment showing the scope of work they will self-certify 
find another endorsed plumber or drainlayer to self-certify the listed work.

Building consent responsibilities

At the building consent stage, BCAs:

still assess designs for compliance with the Building Code
check whether work is eligible to be self-certified.

For any work you want to be self-certified, it must be:

clearly listed in your building consent application
the type of work eligible for self-certification under the self-certification scheme.

How designers contribute to the building consent process

Designers need to provide clear, Building Code-compliant designs and applications to:

support efficient building consent processing
reduce disputes about scope and responsibility
help projects benefit from self-certification where appropriate.

During construction, designers may still be involved in:

amendments or minor variations
resolving design-related issues.