In many cases, yes — a homeowner can demolish a double garage themselves in New Zealand, but there are important legal, safety, and practical steps you must work through before swinging a single sledgehammer. Getting these right protects you, your neighbours, and your new build project.
Do You Need a Building Consent to Demolish?
Demolition of a detached garage may be exempt from requiring a building consent under Schedule 1 of the Building Act 2004, but this is not automatic. The exemption generally applies to small detached buildings, but conditions apply — for example, the structure must not be close to a boundary in a way that affects neighbouring properties, and there must be no dangerous materials concerns that trigger other requirements.
Always confirm with your local council before starting. Requirements vary between territorial authorities, and some councils require a demolition consent or at minimum a notification. Check with MBIE Building Performance for general guidance on Schedule 1 exemptions, then ring your council's building department to confirm what applies in your situation.
Asbestos: The Most Critical First Step
If your garage was built before the mid-1990s, there is a real chance it contains asbestos-containing materials (ACMs). Common locations include:
- Fibrous cement (fibrolite) wall and roof cladding
- Textured ceiling coatings
- Roofing materials and guttering
- Floor tiles and adhesives
Under WorkSafe NZ regulations, you must identify and manage asbestos before any demolition work begins. For a residential homeowner doing their own work, you may be permitted to remove small amounts of non-friable (bonded) asbestos yourself, following strict safety procedures — check current WorkSafe NZ guidance for the applicable threshold and conditions. However, friable asbestos or amounts over 10 m² must be removed by a licensed asbestos removalist. Given the serious health risks, many homeowners wisely choose to hire a professional regardless of the amount.
Have a qualified asbestos assessor inspect the garage before you do anything else. This is not optional — it is a legal and safety requirement.
Disconnecting Services First
Before demolition, all services connected to the garage must be properly isolated or disconnected:
- Electricity: Any electrical work — including disconnecting a sub-board, isolating circuits, or removing wiring — is restricted electrical work and must be carried out by a registered electrician. Check the Electrical Workers Registration Board (EWRB) to find a licensed professional. Do not attempt this yourself.
- Gas: If the garage has a gas connection, disconnection must be done by a licensed gasfitter registered with the Plumbers, Gasfitters and Drainlayers Board (PGDB).
- Water and drainage: Any plumbing disconnection is also restricted work under the PGDB. If your garage has a sink, toilet, or floor waste connected to the public sewer, a licensed drainlayer must handle the disconnection and any capping of pipes.
Never proceed with demolition until you have written confirmation from your tradespeople that all services are safely isolated.
What a Homeowner Can Typically Do Themselves
Once consents are confirmed, asbestos is cleared, and services are disconnected, a competent homeowner can generally carry out the physical demolition of a timber-framed double garage. This typically involves:
- Removing roofing iron, tiles, or other cladding
- Stripping internal linings and insulation
- Dismantling the timber frame
- Breaking up and removing a concrete slab (this is hard work — consider hiring a concrete breaker or mini-excavator)
- Disposing of waste at an approved facility or arranging a skip bin
Tools and Equipment
You'll likely need: a reciprocating saw, circular saw, pry bars, sledgehammer, angle grinder, skip bin or trailer, and appropriate PPE (hard hat, safety glasses, gloves, steel-capped boots, and a P2 dust mask at minimum).
Waste Disposal and Environmental Obligations
Demolition generates significant waste. Treated timber (H3.2 and above), paint containing lead, and other materials may have specific disposal requirements. Check with your local council on approved disposal sites. Burning demolition waste is generally not permitted.
Protecting the Site for Your New Build
Once the garage is down, consider:
- Soil contamination: Old garages can have oil and fuel contamination in the ground. If you're building over the footprint, a soil test may be advisable.
- Retaining existing services: Mark and protect any underground services that will be reused in the new build.
- Site security: Fence off the cleared area, especially if children or the public could access it.
When to Call a Professional
While DIY garage demolition is achievable, there are situations where hiring a qualified demolition contractor is the smarter choice:
- Asbestos is present in significant quantities or is friable
- The garage is attached to or structurally connected to the house
- There are complex service disconnections
- You want the job done quickly and safely with proper waste management
- Your council requires a licensed contractor for the consent
A professional demolition contractor will manage consents, asbestos removal, service disconnections, and waste disposal as a package — saving you considerable stress. You can find experienced local demolition contractors on tradedirectory.co.nz.
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