Last updated:
If your lights flicker, your earth leakage trips for no clear reason, or your COC inspection failed because of old wiring, you may be facing a rewire. It’s one of the bigger electrical jobs a homeowner pays for, so it helps to know what drives the price before you get quotes.
The cost of a full rewire varies a lot from one house to the next. Large or double-storey homes cost more, and the reasons for the difference are explained below.
Supa Nova gives free quotations. Call 011 485 1324 for a price on your job.
Why the range is so wide
Size of the house
More rooms means more circuits, more cable, more plugs and more light points. Electricians often price per point, meaning each plug, light or switch.
Single or double storey
A double-storey home needs cable runs between floors, which takes longer and sometimes means opening ceilings or walls.
Wall construction
Most South African homes have brick walls, so new cable is either chased into the brick and plastered over, or run in surface trunking. Chasing gives a neater finish but adds labour and plastering.
Can the old conduits be reused?
In many homes the existing cables run in conduit pipes inside the walls. If those conduits are in good condition, the electrician can pull out the old cable and pull new cable through without breaking walls. That’s the biggest single factor in keeping the cost down.
The DB board
A rewire usually includes a new DB board with modern breakers, earth leakage protection and surge protection. See DB board replacement.
Upgrades while you’re at it
Extra plugs, outside lights, a stove circuit, or wiring prepared for an inverter all add to the price, but cost far less now than adding them later.
The COC
A rewire must be certified with a new Certificate of Compliance. Make sure the quote includes it.
Signs your house needs rewiring
- The house was built before about 1980 and has never been rewired
- Rubber-insulated cable that crumbles when touched, often found in roof spaces
- Breakers or the earth leakage trip often, especially on particular circuits
- Plugs or switches feel warm, or you see scorch marks
- Lights flicker or dim when appliances switch on
- No earth wire to plugs or lights in older parts of the house
- A failed COC that lists wiring faults
- DIY additions over the years with loose joins in the roof
Any one of these is worth having checked, and the last three often come up together.
Full rewire or partial rewire?
You don’t always need to rewire the whole house. A good electrician tests each circuit for insulation resistance and earth continuity, and tells you which ones fail.
| Situation | Usually |
|---|---|
| A few circuits fail testing, the rest are fine | Partial rewire of those circuits |
| Old rubber cable throughout the roof | Full rewire |
| Extensions added at different times | Rewire the oldest sections |
| New DB board keeps tripping on one circuit | Fix or rewire that circuit |
A partial rewire can cost a fraction of a full one. Ask for a test report before accepting a full-rewire quote.
How long does a rewire take?
A typical three-bedroom house takes from a few days to about two weeks. It depends on the size, whether the conduits can be reused, and how much plastering is needed. You can usually stay in the house, with power restored to each area at the end of each day.
Questions to ask when getting quotes
- Is the price for a full rewire, or only the circuits that failed testing?
- Are the existing conduits being reused?
- Is a new DB board included, and what’s in it?
- Is plastering and painting included, or only chasing?
- Is the COC included?
- What warranty do you give on the workmanship?
Why it matters for Johannesburg homes
Johannesburg has a lot of older housing stock, in suburbs like Orange Grove, Norwood, Houghton, Kensington, Randburg and Bedfordview. Many of these homes still have their original wiring. Add years of load shedding, with surges when power returns, and modern loads like inverters, air conditioners and pool pumps, and old wiring is under more strain than it was designed for.
Get a rewiring quote
Supa Nova’s electricians test your circuits, tell you what needs rewiring and what doesn’t, and quote on that basis. See DB board replacement and rewiring, or call 011 485 1324 or 082 891 1577.