Designers and the plumbers and drainlayers self-certification scheme

What designers need to know

It is the building owner’s choice about whether they want to use self-certification or not.

Building consents can have a mixture of work that has self-certifiable plumbing and drainlaying and work that follows 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.

What work can be self-certified

The scheme applies only to eligible plumbing and drainlaying work:

• on residential, commercial and industrial buildings up to three storeys (except apartment blocks)
• designed to an Acceptable Solution or Verification Method
• for on-site systems – these can be self-certified using a different compliance method if there is no Acceptable Solution or Verification Method that exists for that on-site system.

An on-site system means a system for the independent management of water that does not connect to a network utility operator (NUO) system. This includes systems for circulating, disposing of, storing, supplying, pumping or re-using water, as well as irrigation.

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

Designer responsibilities stay the same

Designers must still:

• 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, provide the name and registration number of the endorsed plumber or drainlayer.

The name and registration number of the endorsed plumber or drainlayer must be provided to the BCA before building work commences. 

Self-certification does not change design standards or obligations.

Coordination with practitioners

If a project intends to use an endorsed plumber or drainlayer:

• designers should clearly show the scope of plumbing and drainlaying work in the application for building consent
• any changes during construction should be managed carefully – endorsed plumbers and drainlayers certify their work complies with the building consent.
  • While endorsed plumbers and drainlayers still can apply for a minor variation, building consent applicants are responsible for applying for amendments to building consents should the scope of work change.
  • There is a risk, should the change not fit the definition of work eligible for self-certifiable plumbing or drainlaying, that normal BCA inspections will apply.

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

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

1. apply for a building consent amendment to reflect the scope of work to be signed off by the endorsed plumber or drainlayer 
2. find another endorsed plumber or drainlayer to self-certify the eligible and listed work.

During the building consent application and once building consent has been issued

At the building consent stage BCAs:

• still assess designs for compliance with the Building Code
• decide 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, as well as fit the definition of eligible plumbing or drainlaying work.

During construction, designers may still be involved in:

• amendments or minor variations
• resolving design related issues.

Why it matters for designers

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.