Bottom line
Different unconsented projects need different evidence.
A deck, bathroom, garage conversion, sleepout or house split will not be assessed the same way. The CoA pathway depends on what was built and what can now be verified.
Common unconsented project types that may need CoA review.
Some completed projects create repeated Certificate of Acceptance issues because they affect structure, moisture, fire safety, drainage, services, use or habitable space requirements.
Garage conversionsDecks and balconiesBathrooms and drainageHouse split issues
Best fit
Who this page is for.
Use this pathway when the situation matches the points on the right. If the work is proposed rather than completed, start with Building Consent Services instead.
Owners who know work was completed but are unsure what evidence type is likely.
Garage, sleepout, deck, bathroom, drainage, second dwelling or structural alteration concerns.
Homeowners deciding whether to use the CoA feasibility check or contact ArchSolutioNZ.
What may be included
The information council may need to understand.
Garage conversion CoA issues: slab moisture, insulation, ventilation, natural light, fire separation and habitable space.
Sleepout and cabin issues: sleeping use, services, exemption limits and detached-building evidence.
Deck and balcony issues: structure, barriers, stairs, durability and safety from falling.
Bathroom and drainage issues: waterproofing, plumbing, drainage and as-built evidence.
Second dwelling and house split issues: fire, drainage, planning, rates and development contribution questions.
Extension and structural issues: removed walls, new openings, additions and hard-to-verify structural work.
Council assessment
What usually drives the CoA risk.
| Issue | What to clarify | Why it matters |
|---|---|---|
| Structure | Deck framing, removed walls, beams, foundations and new openings. | Completed structural work can be difficult to verify without specialist evidence. |
| Moisture | Bathrooms, cladding, decks, balconies, drainage and wet areas. | Moisture failures can remain hidden until damage appears. |
| Use change | Garages, sleepouts, house splitting and second kitchens. | Changing use can trigger fire, ventilation, sanitation and planning issues. |
| Services | Plumbing, drainage, stormwater, wastewater and electrical records. | Service changes usually need credible as-built evidence. |
Process
A practical path through this CoA issue.
1
Review records
We review photos, property file information, LIM notes, owner details, invoices, drawings or council correspondence.
2
Define the scope
We separate what appears to be covered by the CoA question from work that may belong on another pathway.
3
Identify evidence gaps
We identify likely as-built drawings, specialist reports, photos, opening-up or product evidence that may be needed.
4
Prepare next steps
We help organise the documentation pathway before you spend money on the wrong report or application.
Related resources
Keep the wider CoA context close.
The guide explains the rules in plain English, while the free tool helps you check whether the issue appears suitable for a CoA pathway before spending on reports.
Related pathways
Need a different route?
Garage Conversions & Habitable Space ConversionsFor proposed garage conversions before construction starts.Decks, Balconies & Outdoor Living StructuresFor proposed deck and balcony consent drawings.Kitchen, Laundry & Plumbing AlterationsFor proposed plumbing alterations before work starts.Certificate of Acceptance GuideFor the full explanation of CoA rules, evidence, costs, timeframes and possible outcomes.CoA Feasibility CheckFor a quick starting point when you are unsure whether completed work may fit a CoA pathway.Council SupportFor CCC problems, failed inspections, RFIs, Notices to Fix and old consents that were not signed off.Building Consent ServicesFor proposed work before construction starts.
FAQs
Questions homeowners ask first.
Can council accept all completed work through a CoA?+
No. Council can only assess what can reasonably be verified after the work is complete. Hidden work may need opening up, specialist reports, remedial work or may be excluded.
Is a CoA the same as a building consent?+
No. A building consent is for proposed work before construction. A Certificate of Acceptance is a limited pathway for certain completed work that was carried out without the required consent.
What should I send first?+
Send photos, your address, a short description of the work, any council letters, LIM notes, property file information, invoices, drawings or reports you already have.
Does every unconsented project type need the same CoA package?+
No. Evidence depends on the work. A deck may need structural and barrier evidence, while a bathroom may need waterproofing and plumbing evidence.
Official references
Useful official CoA sources.
These references help explain why evidence, scope and verification limits matter.
Need help identifying the right evidence for your project type?
Use the free CoA feasibility check or send us the project details so we can help identify the likely documentation pathway.