Testing decides it. If insulation resistance is poor across the whole installation and the cable is rubber or fabric-sheathed, it is a full rewire — patching one section means the next fails and you pay for the making good twice. A partial rewire is sensible where part of the installation is genuinely sound, typically where an extension or a previous upgrade used modern cable.
- Age is a prompt to test, not a diagnosis. An EICR gives you the evidence.
- Rubber, lead or fabric-sheathed cable is the clearest indicator of a full rewire.
- Most of the cost and disruption is making good, not the cable.
- An empty property is dramatically cheaper and easier to rewire than an occupied one.
Why age alone does not decide it
People ask whether a house of a certain age needs rewiring, and there is no honest answer by date alone. A 1965 house that was partially updated in the 1990s and has been lightly used may test better than a 1985 house that has had thirty years of DIY additions.
What matters is the condition of the cable and the design of the installation, and both are established by testing rather than by looking at the deeds. That is what an EICR is for: insulation resistance results circuit by circuit tell you whether the cable has degraded, and the inspection records whether the design still makes sense for how the house is used.
That said, age is a strong prompt. An installation that has never been updated and dates from before the 1970s is very likely to need substantial work, and the testing usually confirms it.
The evidence that points to a full rewire
| Finding | What it means | Weight |
|---|---|---|
| Rubber, lead or fabric-sheathed cable | Insulation goes brittle and crumbles when disturbed | Decisive |
| Poor insulation resistance across most circuits | Cable degradation is general, not local | Decisive |
| No earth on lighting circuits throughout | Original installation, never updated | Strong |
| Rewireable fuse board with original circuits | The whole installation is of that era | Strong |
| Round-pin sockets anywhere | Pre-1960s wiring still in service | Strong |
| Multiple C2 items across different circuits | Systemic rather than isolated problems | Moderate |
| One circuit failing, rest sound | Localised — a partial is reasonable | Points the other way |
| Modern cable in part of the house | Previous partial work; keep it | Points the other way |
The pattern matters more than any single item. Problems spread across every circuit mean the installation has aged out; problems concentrated in one area mean something happened in that area.
When a partial rewire genuinely works
Partial rewiring has a poor reputation, largely because it is sometimes sold as a cheaper alternative when a full rewire is what is needed. Done for the right reasons it is perfectly sound.
The clearest case is a house where part of the installation is demonstrably modern — an extension wired in the last couple of decades, or a kitchen that was done properly. There is no sense in ripping out good cable to satisfy a principle.
Another is where lighting and power are of different vintages, which is common. Lighting circuits often date from the original installation while socket circuits were upgraded at some point, or the other way round. Testing will show it clearly, and rewiring the failing half is a legitimate answer.
The third is staged work on a property being renovated room by room, where a full rewire is the plan but the budget and the disruption are being spread. That needs designing as a whole from the start so the sections join up properly, rather than being improvised.
When a partial is a false economy
Where the existing cable is at the end of its life, a partial rewire means you will be back. The remaining old section fails next — often within a few years — and at that point you pay again for isolation, testing, certification and, above all, making good.
That last item is the real cost. Rewiring means chasing cables into walls and lifting floors, and the plastering and redecorating that follows is typically the larger part of the disruption and a substantial part of the expense. Doing it twice to the same house is the thing to avoid.
There is also a practical hazard. Rubber-insulated cable is brittle, and disturbing it while working nearby damages it. An electrician working on adjacent circuits can find they have caused faults in cable they never intended to touch, which is uncomfortable for everyone.
What living through a rewire is like
Honest expectations help more than reassurance here.
Cables are chased into walls with a disc cutter, floorboards come up, and ceilings may need accessing from above or below. It is dusty, noisy and intrusive, and the house is effectively a building site while it happens.
Power goes off in sections, and there will be days with limited supply. On a full rewire of an occupied house, expect to be without normal use of rooms in rotation.
After the electrical work comes the making good: filling chases, patching plaster, replacing floorboards, and then redecoration. That stage is often longer than the wiring itself, and it is worth being clear in the quote about who is doing it and to what standard — "make good" can mean anything from filled chases to a finished, painted wall.
Which is why the standard advice holds: rewire before you move in, or alongside other renovation work, rather than as a standalone job in a house you are living in with the carpets down.
What should be in the quote
- The number of circuits and what each one serves — a rewire is a chance to redesign, not just replace.
- Socket and lighting point positions and counts, agreed room by room before work starts.
- The consumer unit specification, including whether RCBOs are used.
- Earthing and main bonding upgrades, which are commonly needed.
- What "making good" means precisely: filled chases, plastered, or plastered and decorated.
- Floor coverings: who lifts and relays, and what happens with laminate or tiles that cannot be relaid.
- The programme, and which rooms are affected when.
- Certification and Part P notification.
Point five is where most rewire disputes start. Agree it in writing.
Use the opportunity
A rewire is the one moment when the walls and floors are open, so things that would be disproportionately expensive later are cheap now.
Worth considering: additional sockets where you actually use them rather than where the 1970s thought you would; data cabling; outdoor power and lighting; a dedicated circuit for a future EV charger; smoke and heat alarm wiring; and ducting for anything you might want later.
Equally worth doing: thinking about how each room is actually used. Most older houses have too few sockets in the wrong places, which is why extension leads proliferate. That is a design problem, and a rewire is the chance to fix it.
What it costs
These are the electrical figures published across this site:
| Job | Typical Coventry guide price | Notes |
|---|---|---|
| Full rewire (3-bed) | £3,000–£6,000 | Whole-house |
| Consumer unit upgrade | £450–£700 | RCD protection |
| EICR (3-bed) | £150–£300 | Safety certificate |
| Electrician, hourly | £45–£90/hr | Certified, Part P |
| Typical job | £233–£473 | Sockets, lighting, faults |
The published rewire figure covers the electrical work. Making good and redecoration vary enormously with the standard you want and should be priced explicitly rather than assumed.
An EICR gives you the evidence rather than a guess, and it avoids both errors — rewiring a sound house and patching one that has aged out.
Frequently asked questions
How do I know if my house needs rewiring?
Get an EICR. Insulation resistance results across the circuits show whether the cable has degraded, and the inspection records whether the design is still adequate. Age is a prompt to test rather than a diagnosis — houses of the same vintage can test very differently depending on what has been done since.
Is a partial rewire a bad idea?
Not inherently. It is sensible where part of the installation is genuinely modern, such as an extension wired recently, or where lighting and power are of different vintages. It is a false economy where the existing cable is at the end of its life, because the untouched half fails next and you pay twice for the making good.
Can I rewire one room at a time?
Yes, as a staged full rewire, and it is a reasonable way to spread cost and disruption during a renovation. The important thing is that it is designed as a whole from the start so the sections join up correctly and the final board is sized for the finished installation, rather than improvised room by room.
Does a rewire include making good?
It depends entirely on the quote, which is why it is the most common source of rewire disputes. "Make good" can mean filled chases, plastered walls, or plastered and decorated. Get the standard written down explicitly, along with who lifts and relays floor coverings and what happens with laminate or tiles that cannot be relaid.
Do I have to move out during a rewire?
Not necessarily, but it is considerably easier if you can, and an empty property is cheaper to rewire because the work moves faster. In an occupied house expect dust, noise, rooms out of use in rotation and days with limited power. Where possible, rewire before moving in or alongside other renovation work.
How long does a full rewire take?
For a typical three-bedroom house, commonly a week or so for the electrical work itself, plus the making good afterwards — which is frequently the longer stage. An occupied house takes longer than an empty one, because access has to be worked around daily life.
Let the testing decide
We test before recommending, so you are not rewiring a sound installation or patching one that has reached the end of its life. Free quote, certificated work.