A tingle, a hot smell or a scorched power point? Do this first
If a tap, appliance or switch gives you a shock or a tingle, or you can smell something hot and can't find it, switch off at the main switch if you can reach it safely and keep everyone away from that fitting. Smoke, fire or someone hurt means 111, and never touch a person who may still be in contact with the power. Electricity Networks Aotearoa (ENA) says burn marks, odd smells or crackling at the switchboard are a reason to leave it untouched and ring your lines company straight away.
Signs the wiring is wearing out
- Black rubber or cloth-covered cable in the ceiling space or under the floor that cracks or flakes when it's moved.
- Scorch marks, melted plastic or a fishy, plasticky smell around a switch or power point.
- Fittings that feel warm with hardly anything plugged in.
- Lights that flicker or dim whenever a big appliance starts.
- So few power points that the house runs on multiboards and extension leads.
- Wiring a past owner added with no paperwork, like joins wrapped in tape in the roof space.
Full rewire or part rewire?
A full rewire replaces the cable to every light and power point, and usually the switchboard with it. It's the answer when the old cable is failing throughout, or when the linings are coming off anyway for a big renovation.
A part rewire replaces the worst circuits first, often the oldest lighting runs, the kitchen or a bathroom. It makes sense when testing shows the rest is sound. Ask for the readings in writing, so the decision rests on numbers from an instrument, not a hunch.
There's no single age at which wiring fails. Heat, damp, rodents and earlier DIY matter more than the year the house was built, so testing should come before any quote for a full rewire.
What happens on a rewiring job
The electrician tests the existing circuits, plans the new cable routes, then runs new cable through the ceiling space, under the floor and inside the walls. Fittings go back on, often in better spots, and every circuit is tested before the power is restored.
Most families stay in the house, with the power off in sections during the day. Expect a few small holes in the linings where cable can't be fished through, and agree up front who patches and paints them.
Under WorkSafe's guidance, new lighting and power point circuits that start at a home's switchboard need RCD protection by law. A rewire creates new circuits, so an old board with no room for RCDs is usually replaced as part of the same job.
The certificates, and when an inspection comes in
The EWRB (Electrical Workers Registration Board) classes a rewire as general work. The electrician must give you a Certificate of Compliance (CoC) describing the work, its dates and its test results, and an Electrical Safety Certificate (ESC) once the work is livened and confirmed safe to use.
If the rewire includes a higher-capacity switchboard or any mains work, that part becomes high-risk work. A licensed electrical inspector then checks it independently and issues a Record of Inspection, and the job isn't legally complete until the CoC and that record have both been issued.
Ask for your certificates as soon as the work is finished and file them with the house papers. According to the EWRB, a CoC can be needed for an insurance claim or when the house is sold.
Rentals, insurance and the new wiring rules
In a rental, landlords and tenants can't do electrical work unless they're registered and hold a current practising licence, so a landlord's rewire always goes to a licensed electrician. The EWRB also warns that unlicensed work can affect your insurance and is often unsafe.
Electrical workers have until 12 November 2026 to move to the updated wiring rules, AS/NZS 3000:2018. That doesn't put a deadline on your house: WorkSafe's guidance lets an existing installation stay in service, and be repaired, for as long as it isn't unsafe. Failing cable is the reason to rewire, not a new standard.
Can a homeowner do any of the wiring?
Only a very little, and only on a home you own and live in, never for payment and never in a rental. The EWRB says any wiring a homeowner adds must be tested and connected to the supply by a licensed electrical inspector, and switchboard and meter work is off limits altogether. WorkSafe New Zealand's guidance sets out the narrow limits, and what you can do yourself explains them. For a rewire, we wouldn't go near it.
What you can do, and what needs a licence
You can
- Write down which lights or power points misbehave, and when, so the electrician starts with facts.
- Reset a tripped breaker or RCD once. If it trips again, leave it off and call an electrician.
- Photograph any old cable you can see from the ceiling hatch, without touching it.
- Clear the way to the ceiling space and underfloor before the electrician arrives.
Leave to a licensed electrician
- Running new cable and adding or extending circuits.
- Anything inside the switchboard or meter board.
- Testing the old wiring and deciding what can stay.
- Arranging the licensed electrical inspector if any part is high-risk work.
Questions to ask before you say yes
- Have you tested the existing wiring, and can I see the results?
- Is this a full or a part rewire, and which circuits are included?
- Does the switchboard need replacing, and would that make any part high-risk work?
- Who patches the holes in the linings, and who paints?
- How long will the power be off each day?
- Can I see your licence ID so I can check you on the public register?
Why a rewiring specialist
Rewiring a lived-in house is its own skill. An electrician who does it most weeks knows how to get cable through villa walls and bungalow ceilings with the least damage, and plans the work so the fridge stays on and the kids can still sleep. Mention the age of the house and any renovation plans, and we'll match you with one licence-checked local electrician who rewires older homes.
Where we'd start
We'd get the wiring tested before deciding anything. If the readings say it's failing, we'd rewire in one go with the linings off and replace the board at the same time, adding the power points the next ten years will need. If only part of it is failing, a staged rewire is fine, as long as the circuits you keep have test results behind them.
Want a specialist to sort it?
Tell us the job and your postcode. We match the licence-checked local electrician who does this kind of work, and they call you. No ring-around, and your number goes to them alone.