A Certificate of Acceptance, often called a CoA, can help resolve certain building work completed without a building consent. It is not a retrospective consent, and it does not give full assurance for hidden work.
Bottom line
Start by proving what was built, when it was built and how it meets the Building Code. The more work is hidden behind linings, foundations, waterproofing or services, the more evidence council will usually need and the more likely the certificate may include exclusions.
Clear definition
A Certificate of Acceptance is a council-issued certificate for specific building work that was carried out without a building consent, or where a Code Compliance Certificate cannot be issued in limited situations. In most homeowner cases, it is used for unconsented work completed after 1 July 1992.
It can also apply to urgent work carried out under section 42 of the Building Act 2004, or a limited specialist BCA scenario where a CCC cannot be issued.
Key idea: council can only assess what it can reasonably see, test or verify after the work has already been completed.
A building consent is normally issued before work starts, not after it is finished.
A Code Compliance Certificate confirms work complies with an issued consent. A CoA is more limited.
Councils may still issue notices, require remedial work or take enforcement action.
Council risk
Council did not inspect the work during construction. That means some elements may now be difficult, expensive or impossible to verify without opening up the building.
Common problem areas include foundations, framing, structural connections, fire separations, waterproofing, plumbing, drainage, insulation and services hidden behind linings. If council cannot reasonably inspect or verify those elements, the CoA may be qualified or exclude parts of the work.
Practical takeaway: the more closed-in the work is, the stronger your evidence needs to be. Photos, invoices, producer statements, specialist reports and accurate as-built drawings can make a major difference.
Process map
The process usually turns on evidence: what council can verify, what professionals can certify and what remains hidden or uncertain.
Councils often need similar information to a building consent application, plus extra evidence proving what was actually built.
| Issue | What to expect |
|---|---|
| Processing time | Councils commonly work to a 20-working-day timeframe once the application is complete. RFIs can pause processing while additional information is prepared. |
| Council fees | Fees vary by council and complexity. You may also need to pay fees, charges or levies that would have applied if consent had been sought before the work was carried out. |
| Professional costs | As-built drawings, engineering, fire, drainage, building surveying and other specialist evidence can become a major part of the total cost. |
| If issued | The CoA identifies the work covered and what was inspected or assessed. It may include qualifications or exclusions for hidden work. |
| If refused | Council must explain why. A Notice to Fix may require remedial work so the work can comply with the Building Code. |
Describe what was built, when it was built, who did the work and what evidence exists.
As-built plans should match the site, not what someone wishes had been built.
Closed-in structural, waterproofing, drainage or fire elements usually need stronger evidence.
A CoA does not replace planning approvals, title checks, cross-lease approvals or resource consent.
The certificate identifies the work assessed and may record qualifications or exclusions for work council could not verify.
Council must give reasons. You may need remedial work, removal, further assessment or a different compliance pathway.
Costs vary by council and complexity. Expect council processing fees plus professional fees for as-built plans, engineering reports and specialist assessments. Complex projects with closed-in work can cost several thousand dollars or more.
Councils commonly work to a 20-working-day processing timeframe once the application is complete. Requests for further information can pause the clock, so total timelines often extend beyond the base processing period.
No. A COA gives limited assurance only for what council can reasonably assess after the work has been completed. Hidden or closed-in elements may be qualified or excluded.
Generally no. The Certificate of Acceptance pathway applies to certain building work carried out after building consents were introduced on 1 July 1992.
It depends on the work. Structural, fire, drainage, waterproofing or complex alterations often need professional assessment. Most COA applications benefit from clear as-built drawings and coordinated evidence.
You may be able to sell, but unconsented work can affect buyer confidence, legal due diligence, lending, insurance and price negotiation. Get legal advice before relying on a sale strategy.
Council must explain the reasons. You may need remedial work, removal, more evidence or another pathway. In some cases a Notice to Fix may be issued.
A CoA does not prevent enforcement action. Councils often focus on compliance and safety, but notices, remedial requirements or enforcement action remain possible depending on the circumstances.
Official references
This article is general guidance only. For formal requirements, check the Building Act, MBIE Building Performance guidance and your local council.
Author
Founder, Director and NZ Registered Architect. NZRAB Registration No. 6195.
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