Unconsented Works Explained
Insight
Unconsented building work is one of the most common legal issues discovered during property transactions in New Zealand. These issues can range from small DIY alterations to major structural additions that were never approved by council. Because unconsented work may not comply with the Building Act or current standards, it can affect lending, insurance, value and resale.
Buyers often discover unconsented works only when reviewing the LIM report or when a building inspector finds inconsistencies. Sellers may also be unaware of historic work completed by previous owners. Council notices—such as outstanding consents, failed inspections or hazard warnings—can add further risk.
People typically seek help when reviewing LIM entries that raise concerns, when buying a property with visible alterations, or when a seller cannot provide documentation for completed works.
What Counts as Unconsented Work
Insight
Unconsented work is extremely common and not always a deal-breaker. The key question is whether the work poses a safety risk, an insurance problem, or a future cost.
Unconsented work refers to any building activity carried out without the approvals required at the time. This usually means the absence of a building consent, but it also includes changes that should have triggered inspections, producer statements, or compliance sign-off.
Common examples include:
- Altering internal walls or room layouts
- Adding bathrooms, laundries, or kitchens
- Installing decks, retaining walls, or pergolas
- Converting garages, sleepouts, or basements into living areas
- Replacing structural elements (beams, supports, roofing sections)
- Electrical or plumbing work completed without certification
Older properties often contain historical works completed long before modern compliance rules. The issue is not the age of the work, but whether it meets today’s standards and whether it exposes a buyer to risk.
Why Unconsented Work Causes Problems
Unconsented work can affect a sale in several ways:
Insurability:
Insurers may deny cover if unapproved alterations contribute to damage. Some require evidence of consent before offering a policy.
Market value:
Buyers often use unconsented work to negotiate a lower price or require the seller to fix issues before settlement.
Financing:
Banks may decline lending if the security property contains work considered non-compliant or unsafe.
Legal liability:
Owners may be required to remediate defective work, and in some cases councils can issue notices requiring corrective action.
Even when a property appears sound, missing paperwork can slow or derail a transaction.
Common Pitfalls
Most pitfalls occur not because unconsented work exists, but because the buyer didn’t fully understand the cost, risk or process required to resolve it.
Hidden structural changes
Walls removed, beams added, or rooflines altered without drawings or inspections. These carry the highest risk because they may fail under load or weather conditions.
Wet-area additions
New bathrooms, laundries, or kitchenettes are common sources of leaks. When work was done without waterproofing certification, insurers may refuse related claims.
Garage and sleepout conversions
Many conversions appear tidy but do not meet standards for insulation, moisture, ventilation, or fire safety. They often fall well short of requirements for habitable spaces.
“Minor” work that isn’t minor
Owners frequently assume that small projects — decks, retaining walls, internal repairs — do not require approval. Many of these do once specific height, size, or structural thresholds are crossed.
How to Assess Whether the Work Is Legal
You cannot assess legality by looking at the house alone. You must compare the property’s physical features with the council record, the historical rules, and the actual construction details.
A thorough assessment goes beyond reading the LIM report. Follow a structured process:
Compare the property to the approved plans
Check council records for existing consents, drawings, and code-compliance certificates. Compare these to what physically exists on site.
Inspect high-risk areas
Wet areas, external structures, and any altered load-bearing walls should be inspected by a qualified builder, engineer, or building surveyor.
Confirm electrical and plumbing certification
Even if the building work is unconsented, electrical and plumbing must still be certified. Missing or incomplete certificates are a red flag.
Assess safety and compliance
The key issue is whether the work meets today’s standards. Even compliant historical work may need upgrading if it presents a genuine hazard.
Get legal advice early
Lawyers can interpret council records, identify missing documents, and advise on how the risk affects your ability to buy, sell, or finance the property.
Potential Costs of Unconsented Works
The true cost of unconsented work is rarely the visible alteration — it’s the cost of proving compliance, meeting modern standards, and resolving insurance and lending risks.
The financial impact varies widely. Costs can include:
Remedial building work
Fixing leaks, replacing non-compliant materials, or rebuilding unsafe structures.
Retrospective approval costs
Applying for a certificate of acceptance often requires engineering reports, invasive inspection, and additional documentation.
Property devaluation
Buyers may negotiate significant price reductions, especially for structural or watertightness issues.
Insurance complications
Some insurers load premiums or refuse cover until unconsented work is addressed.
These costs should be factored into negotiations to avoid unpleasant surprises later in the transaction.
When to Seek Legal Advice
You should speak to a lawyer if:
- You are buying a property and notice inconsistencies between plans and what is on site
- A builder or inspector identifies unapproved alterations
- There is missing paperwork relating to past work
- The seller cannot explain how or when certain alterations were done
- You need help preparing an offer that protects you
A lawyer can help:
- Review the LIM and council file
- Confirm what approvals should have been obtained
- Structure the contract to allow proper investigation
- Advise whether to seek a price reduction or request remedial work
- Support applications for retrospective approval
- Communicate with the bank or insurer where needed
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Frequently Asked Questions
What counts as unconsented work?
Unconsented work includes any building alterations or additions completed without the required council building consent. This could involve decks, garages, extensions, structural changes, plumbing work or sleepouts. If the work required consent but none was obtained, the issue appears on the LIM or becomes a risk during due diligence.
Why are unconsented works a problem?
Unconsented works can impact insurance, lending, resale value and legal compliance. Banks may decline lending if work is not approved, and insurers may refuse cover for related damage. Some buyers face unexpected repair costs or compliance requirements after settlement.
Can unconsented work be legalised later?
Possibly. A Certificate of Acceptance (CoA) may be available, but it depends on whether the work meets current building standards and whether it can be inspected. Some work cannot be retroactively approved, especially if it involves hidden construction that cannot be assessed.
What if a LIM shows 'outstanding building works'?
A LIM may list incomplete consents, failed inspections or outstanding council actions. These may require completion, compliance work or clarification before going unconditional. Your lawyer explains the seriousness of the notice and whether further reports or negotiations are needed.
Can I negotiate price because of unconsented works?
Yes. Buyers often negotiate price reductions when unconsented work or council notices appear in the LIM. A lawyer can help you determine whether negotiation is appropriate and what risks remain even after a discount.
You don’t need all the answers
Property issues can feel overwhelming — especially when you’re facing deadlines. Sharing a few details about your situation is enough for a lawyer to understand the context and guide you through the next steps.
Get Help With Unconsented Works
Unconsented alterations can affect insurance, valuation, lending, and the ability to sell. If you’re unsure whether past work is compliant—or you’ve discovered alterations during due diligence, you can connect with a property lawyer who deals with these situations daily.