Why guarantees matter in demolition work
Demolition might look straightforward, but there is a lot that can go wrong: damage to neighbouring property, unsafe site clean-up, missed utilities, incomplete removal of materials, poor dust control, or extra costs because the contractor underestimated access and disposal. For homeowners, a clear guarantee is one of the best ways to reduce risk.
A good demolition contractor should be willing to stand behind both their workmanship and the materials or equipment they supply. In New Zealand, you also have legal protection under the Consumer Guarantees Act 1993 (CGA), which applies to most services supplied to households.
That said, guarantees and warranties are not all the same. Some are voluntary promises. Others are provided by law. Knowing the difference helps you compare quotes properly and avoid paying extra for protections you already have.
Workmanship guarantees: what they should cover
A workmanship guarantee is the contractor’s promise that their work will be carried out with reasonable care and skill, and that any faults caused by poor workmanship will be put right at no extra cost within a stated period.
For demolition, a workmanship guarantee should ideally cover:
- safe dismantling or demolition carried out to the agreed scope - protection of parts of the property that were meant to remain - removal of debris and making the site safe and tidy - dust, noise and vibration control measures promised in the quote - correct separation and disposal of waste, including hazardous materials if identified and included in the job - repair of accidental damage caused by the contractor, subject to the contract - completion of any agreed documentation, such as waste disposal records or site sign-off
A contractor may offer a guarantee period of 30 days, 90 days or longer, but the length matters less than the wording. The key question is: what happens if the work is defective, incomplete or unsafe?
What a good workmanship guarantee looks like
Ask for the guarantee to be in writing and to include:
- the exact work covered - the length of the guarantee period - what counts as a defect or failure - how to notify the contractor - timeframes for them to inspect and fix the issue - whether the contractor covers call-out, labour, disposal and rework costs - exclusions, such as damage caused by the homeowner or another tradesperson
Be cautious if the guarantee is very vague, for example: “All work guaranteed” with no details. That can be hard to enforce.
Product warranties: when they matter in demolition
Demolition contractors usually provide a service rather than a product. However, product warranties can still matter if the job includes supplied items such as:
- temporary fencing - safety barriers - dust-suppression equipment installed as part of the job - locks, seals or weatherproofing materials used to secure the site after demolition - bins, skips or portable site amenities included in the package
Product warranties come from the manufacturer or supplier and typically cover defects in the item itself, not poor installation or misuse by the contractor.
If a demolition contractor supplies products as part of the job, ask:
- whose warranty applies - how long the warranty lasts - who provides the paperwork - whether the warranty is transferable if the item remains on the property - whether installation is included in the warranty conditions
A useful quote should separate labour, disposal, and any supplied products so you can see where warranty responsibilities sit.
The Consumer Guarantees Act: your built-in protection in NZ
For most homeowners in New Zealand, the CGA is the most important protection. If a demolition contractor is supplying services to a household, those services must be carried out with:
- reasonable care and skill - fitness for purpose, if you told them what you needed and they agreed to that outcome - completion within a reasonable time, if no time was agreed - a reasonable price, if the price was not fixed in advance
This matters because even if a contractor’s own guarantee is weak or absent, they still cannot contract out of the CGA for most residential work.
In practical terms, if demolition work is faulty, incomplete, unsafe, or not what was agreed, you may be entitled to have it fixed, redone, or to seek a reduction in price or a refund depending on the seriousness of the problem.
What counts as faulty demolition work?
Examples may include:
- a wall or structure that was meant to remain gets damaged - debris is not removed as agreed - the site is left unsafe or unsecured - asbestos or other hazardous material issues are ignored after being raised - utilities were not properly isolated and damage occurs - the contractor failed to follow the agreed scope or method - the job takes far longer than reasonably expected without good reason
Not every disappointment is a breach. For example, unexpected conditions found during demolition can increase cost or time if the contract allows for variations. This is why a clear scope and written variation process are so important.
What a demolition contractor should put in writing
Before work starts, ask for a detailed written quote or contract. This is where warranty and guarantee terms should be spelled out.
| Item | What to check | |---|---| | Scope of work | Exactly what is being demolished, removed and made safe | | Exclusions | Anything not included, such as asbestos removal, drainage, electrical disconnection or salvage work | | Warranty/guarantee | What is covered, for how long, and how to make a claim | | Damage responsibility | Who pays if the contractor damages retained structures, fencing, driveways or neighbouring property | | Site condition at handover | Whether the site will be levelled, backfilled, cleaned or left in a specific condition | | Disposal | Who is responsible for legal disposal and landfill fees | | Variations | How extra work or unforeseen hazards will be priced and approved | | Insurance | Evidence of public liability insurance and, where relevant, contract works cover |
If a contractor refuses to put these details in writing, that is a red flag.
Special rules and checks that affect demolition jobs
Demolition work often sits alongside other regulated trades, so one contractor’s warranty may not cover everything.
Building consents and local council requirements
Some demolition work may require a building consent or other council approval, particularly where a building is being removed in a controlled way, structural elements are involved, or the work affects fire safety, boundary conditions or shared services. Requirements vary by local council, so always check before work begins.
Even where no consent is needed, the contractor should still follow safe work practices and any conditions imposed by the council.
Asbestos and hazardous materials
Older NZ homes can contain asbestos in roofing, cladding, vinyl, insulation, pipes or linings. If asbestos is present or suspected, it must be handled in accordance with health and safety requirements.
A demolition contractor should clearly state whether asbestos assessment or removal is included. In many cases, this is specialist work and may be excluded from a standard demolition quote. Do not assume a demolition warranty covers hazardous materials unless it says so.
Electrical, gas, plumbing and drainage disconnections
Demolition often requires services to be safely disconnected before work begins. In New Zealand:
- electrical work is regulated by the Electrical Workers Registration Board (EWRB) - plumbing, gasfitting and drainlaying are restricted work under the Plumbers, Gasfitters and Drainlayers Board (PGDB)
A demolition contractor should not carry out restricted work unless properly licensed and authorised. If they are coordinating disconnects, ask who is doing the work and whether those trades will provide their own compliance records and warranties. For example, a qualified electrician should issue the relevant electrical certificate, and any gasfitting or drainlaying work must be done by the right registered professional.
What happens if the contractor’s work is faulty
If the demolition work is not up to standard, act quickly and keep records.
Step 1: Document the problem
Take dated photos and video. Keep copies of:
- the quote and contract - texts and emails - invoices and receipts - any site instructions you gave - notes of phone calls, including dates and names
Step 2: Notify the contractor in writing
Tell them exactly what is wrong and what remedy you want. Be specific, for example:
- repair damage to the retained garage wall - remove debris left on site - secure the site fence - complete the agreed cleanup - refund part of the fee for work not completed
Give a reasonable deadline for response and action. For urgent safety issues, ask for immediate attendance.
Step 3: Use the contract and the CGA
If the contractor disputes the issue, refer to the written agreement and the CGA. In many cases, a contractor will prefer to fix the problem rather than face a formal dispute.
Step 4: Escalate if needed
If the contractor will not resolve the issue, you may be able to:
- use a disputes tribunal or the District Court, depending on the amount and complexity - make a claim under the contractor’s insurance if property damage is involved - complain to a relevant trade association if they belong to one - seek advice from the Citizens Advice Bureau or a lawyer
If there is immediate risk to health or safety, contact the local council or the relevant authority.
What to ask before you hire
When comparing demolition quotes, ask these practical questions:
- What exactly is covered by your workmanship guarantee? - Do you provide a written contract with warranty terms? - Are any hazardous materials excluded? - Who disconnects power, gas, water and drainage? - Do you have current public liability insurance? - Will you provide disposal records if requested? - What happens if you damage retained parts of the property? - How do you handle unforeseen issues like buried foundations or asbestos?
Also ask for at least two or three written quotes. In the NZ market, pricing can vary a lot depending on access, region, disposal fees, and whether the work is in a busy urban area or a rural site with longer haulage distances. A quote that is much cheaper than the others may have excluded important protections.
Red flags that suggest weak aftercare
Be wary of contractors who:
- won’t provide a written quote or contract - promise a guarantee but won’t explain what it covers - exclude almost everything from the warranty - pressure you to pay in full upfront without milestones - cannot show current insurance - are vague about consents, service disconnections or disposal - say “that’s just how demolition is” when you raise a legitimate defect
A strong contractor does not need to oversell guarantees. They should be clear, professional and easy to hold accountable.
Final takeaways for homeowners
For demolition work in New Zealand, the most useful protection is a combination of a clear written contract, a sensible workmanship guarantee, any applicable product warranties, and your rights under the Consumer Guarantees Act.
Before you sign, make sure you know:
- what the contractor is actually responsible for - what is excluded - who handles consents, disconnections and hazardous materials - how faults will be fixed if the job goes wrong
If the answer to any of those questions is unclear, get it clarified in writing before work starts. That is the best way to avoid disputes later and make sure the demolition is done safely, legally and to a standard you can rely on.