If you uncover old wiring during a DIY strip-out, stop work immediately and do not touch the wiring. Old electrical wiring can be dangerous, and in New Zealand, almost all electrical work — including disconnecting or removing wiring — is legally restricted to licensed professionals. Here's what you need to know to stay safe and on the right side of the law.
Stop Work and Assess the Situation
The moment you expose wiring you weren't expecting, put down your tools. Old wiring in New Zealand homes can include aluminium wiring, rubber-insulated cables (common pre-1970s), or even lead-sheathed wiring in very old homes. These can be brittle, degraded, or simply not up to current standards. Damaged insulation can cause electric shock, arc faults, or fires — even if the circuit appears to be switched off at the board.
Do not assume a circuit is dead just because you've flicked a breaker. Always treat exposed wiring as live until a licensed electrician confirms otherwise.
What Is Legally Restricted Electrical Work in NZ?
Under the Electricity Act 1992 and associated regulations, electrical installation work is restricted work in New Zealand. This means only a registered electrician (or someone supervised by one) can legally:
- Disconnect, remove, or re-route wiring
- Isolate circuits at the switchboard
- Test whether wiring is live or dead
- Make any connections or alterations to the electrical installation
The Electrical Workers Registration Board (EWRB) maintains the register of licensed electricians. Hiring an unlicensed person — or doing restricted electrical work yourself — is illegal and can void your home insurance.
As a homeowner, you cannot do this work yourself, even on your own property.
What You Can Do as a Homeowner
While you must leave the wiring itself alone, there are a few sensible steps you can take:
- Turn off the relevant circuit at the switchboard if you can identify it safely — but do not touch the wiring itself
- Mark the area clearly so no one else on site accidentally contacts the wiring
- Photograph what you've found — this helps the electrician understand the scope of work before they arrive
- Contact a licensed electrician to assess and safely deal with the wiring before you continue your strip-out
Recognising Potentially Hazardous Old Wiring
Not all old wiring looks the same. Here are some types to be aware of:
| Wiring Type | Approximate Era | Key Risk |
|---|---|---|
| Rubber-insulated (black/brown) | Pre-1970s | Brittle insulation, prone to cracking |
| Aluminium wiring | 1960s–1970s | Loose connections, fire risk |
| Lead-sheathed cable | Pre-1950s | Degraded insulation, potential lead exposure |
| Unsheathed twin (no earth) | Pre-1970s | No earth conductor, shock risk |
If your home is older and hasn't had a full rewire, there's a reasonable chance you'll encounter at least one of these. An electrician can advise whether the wiring needs to be replaced entirely or can be safely retained.
Building Consents and Your Strip-Out
Depending on the scope of your project, your strip-out may require a building consent. Under Schedule 1 of the Building Act 2004, some minor work is exempt — but removing linings, structural elements, or anything that affects weathertightness or fire separation typically requires consent. Always check with your local council before starting demolition work.
The MBIE Building Performance website has clear guidance on what requires consent and what doesn't. When in doubt, ask your council — getting it wrong can create serious problems when you sell or insure your home.
Asbestos: Another Hidden Hazard
While you're stopped and waiting for the electrician, take a moment to consider asbestos. Homes built before 1990 may contain asbestos-containing materials (ACMs) in textured ceilings, vinyl floor tiles, wall linings, and pipe lagging. Disturbing these during a strip-out is a serious health risk.
WorkSafe NZ has detailed guidance on identifying and managing asbestos in DIY situations. If you suspect ACMs, get a licensed asbestos assessor involved before continuing.
When to Call a Professional
Call a licensed electrician before continuing any strip-out work where wiring has been exposed. This is not optional — it's a legal requirement. A good electrician will isolate the affected circuits, assess the condition of the wiring, and advise you on next steps. They can also issue the required Certificate of Compliance (CoC) for any electrical work carried out.
If your project is large-scale — such as a full renovation or partial demolition — consider engaging a demolition contractor who is experienced in coordinating with electricians, plumbers, and other trades. You can find qualified local demolition contractors and electricians on tradedirectory.co.nz.
SiteWise
Tōtika Prequalified
ISO 45001
