7.1 Certifying Authority, Producer Statements & Records of Work

Certifying authority and documentation

A certifying drainlayer is responsible for their own work and for adequate supervision of restricted work carried out under their authority. Documentation should make that responsibility visible without claiming powers the practitioner does not hold.

Ordinary certifying authority

The certifying class is the highest drainlaying registration class. With a current practising licence, the practitioner may perform the work within scope and supervise others as permitted by the Act. The certifier must know the work, direct and monitor it at a level suited to the person and risk, inspect critical stages, and verify the finished result.

This authority is not a general power to certify any drainage project. Public-network approvals, building consent, resource consent, specialist design, and the Building Code remain applicable.

Self-certification endorsement

From 7 September 2026, the statutory self-certification scheme permits eligible consented work to be self-certified only by a certifying plumber or drainlayer who holds the specific self-certification endorsement. The Board’s current application material requires a current certifying licence, completion of the prescribed training, appropriate insurance, business systems and records, and payment of the applicable fee and audit levy.

A certifying-drainlayer licence without that endorsement is not self-certification authority. The endorsement also does not make every project eligible. Check the Act, regulations, Board conditions, eligible-work definition, consent documents, and audit obligations before using the pathway.

Records of work and project evidence

The current Act includes record-of-work provisions introduced by the recent amendments. Use the Board’s current form and directions for when, by whom, and to whom a record must be provided. Do not substitute an obsolete Building Act section or a locally invented certificate.

Project evidence may include approved plans and variations, site instructions, licence and supervision records, product data, inspection photographs, levels, test sheets, as-built drawings, network approvals, commissioning reports, and maintenance information. Each item has a purpose; a photograph does not prove a pressure test, and a test does not prove gradient.

Producer statements

Producer statements are commonly used as supporting evidence in New Zealand building-control practice, but they are not themselves a universal statutory licence, certificate, or mandatory form for every drain. A BCA decides what evidence it will consider on reasonable grounds, subject to the consent and its procedures. Sign a PS3 or similar statement only if requested or accepted and only within the signer’s competence and direct knowledge.

Honest scope

Write what was actually done. “I inspected the open trench on these dates and witnessed this named test” is stronger than “all work guaranteed compliant” when part of the system was outside the certifier’s observation. Identify reliance on a designer, surveyor, laboratory, treatment-unit technician, or network approval.

Documentation review

For a gravity drain, the closeout file might contain the consented plan, authorised variation for a reroute, supervision log, open-trench photographs, G13 test sheet, invert survey, as-built plan, and BCA inspection record. For an on-site treatment system, add the site-and-soil assessment, design report, regional or district approvals, commissioning data, owner manual, and maintenance agreement where required.

If a document contains an error, correct it transparently. Preserve version history and explain the change rather than silently altering the original. Good records enable the BCA, owner, supervisor, and future drainlayer to understand the installed system.

Independent source-check exercise

For 7.1 Certifying Authority, Producer Statements & Records of Work, practise answering from evidence rather than recall. Write the controlling source, its edition or effective date, its scope, and the exact paragraph, table, figure, or manufacturer instruction that supports the decision. Then state the site inputs that can change the result. In this section those inputs include Certifying registration and a current licence do not automatically include the self-certification endorsement.; From 7 September 2026, eligible consented work may be self-certified only by a certifying practitioner holding the specific endorsement and meeting its conditions.; Producer statements are evidence used by some BCAs; they are not statutory licences and are not universally required..

Build a four-column check: proposed condition, source requirement, evidence observed, and action. Test the answer with one changed assumption. A different pipe size, discharge-unit load, ground condition, licence status, authority, compliance path, or consent condition may produce a different result. If it does, explain why; if it does not, show which requirement remains controlling.

Finish with a field-verification plan. Name what must be inspected before concealment, what instrument or record demonstrates it, who has authority to accept a change, and what appears on the as-built or completion file. This exercise turns an open-book fact into certifying-level judgement. It also exposes accidental mixing of standards: if the source for a dimension differs from the source for the test or approval, either return to one complete compliance path or document the proposal as an Alternative Solution. Do not promote an example value into a national rule.