A full rewire replaces every cable, socket, switch and the consumer unit throughout a property. It is needed when the existing installation has degraded past safe repair, most commonly where rubber or fabric insulated cable is still in place, or where an electrical inspection has returned unsatisfactory codes across multiple circuits. Age alone is not the deciding factor, condition is.
Key Takeaways
- Rubber, lead or fabric insulated cable means a rewire, not a repair.
- An EICR is the proper way to establish whether a rewire is genuinely needed.
- Partial rewires are legitimate where only certain circuits have failed.
- Notifiable work must be certified and reported to building control.
- A rewire is far less disruptive when combined with other renovation work.
What Are the Real Warning Signs?
The clearest indicator is the cable itself. If you can see cabling with a rubber or cloth outer sheath, or lead sheathing, the installation dates from a period when insulation degraded with heat and age. That material becomes brittle, cracks at bends and terminations, and eventually exposes conductors inside walls and ceilings where you cannot see it happening.
Beyond the cable, look at what the installation is asking you to live with. Frequent tripping that has no obvious cause, sockets or switch plates that feel warm, a persistent smell of hot plastic, lights that dim when an appliance starts, and brown bakelite fittings are all worth investigating. None of them individually proves a rewire is needed, but together they build a picture.
The other common trigger is simply that the installation was designed for a different era of electricity use. A house wired in the 1970s was never intended to run a home office, an induction hob, an electric shower and a car charger. Where circuit capacity is the limitation rather than cable condition, our NICEIC qualified electricians can often add circuits and upgrade the consumer unit without a full rewire.
How Do You Establish What Is Actually Needed?
With an Electrical Installation Condition Report. An EICR is a formal inspection and test of the fixed wiring, and it produces coded observations that tell you exactly where you stand. It is the difference between an informed decision and a guess, and it is the document any competent electrician will want to see before quoting for a rewire.
| Code | Meaning | What it implies |
|---|---|---|
| C1 | Danger present, immediate risk of injury | Must be made safe on the spot, before anything else |
| C2 | Potentially dangerous | Requires remedial work, and multiple C2s across circuits often point to a rewire |
| C3 | Improvement recommended | Not a failure, but worth addressing during other work |
| FI | Further investigation required | Something could not be assessed and needs following up |
How EICR observation codes translate into action.
An overall unsatisfactory result driven by a handful of localised C2 items usually means targeted remedial work. An unsatisfactory result where the same problems recur on every circuit, particularly deteriorated insulation or absent earthing, is what genuinely justifies replacing the installation. The report gives you that distinction in writing.
Full Rewire or Partial Rewire?
Partial rewires are entirely legitimate and often the sensible answer. Where a property has had its lighting circuits replaced at some point but retains original ring finals, or where an extension was wired to current standards while the original house was not, replacing only the failed sections is proportionate.
The judgement call is whether mixing old and new leaves you with an installation that is coherent and testable. If the old sections will need attention within a few years anyway, and the access work has already been done for the new sections, doing it all at once is usually the better value decision. This is especially true during a full house renovation when floors are up and walls are open.
What happens during a rewire
1 Inspection and design
The existing installation is tested, circuits are designed for how you actually use the house, and socket and switch positions are agreed room by room.
2 First fix
Floorboards come up and walls are chased for cables. New cabling is run back to the consumer unit position and every accessory point is prepared.
3 Consumer unit and earthing
The new consumer unit goes in with residual current protection, and main protective bonding to gas and water services is brought up to standard.
4 Second fix
Sockets, switches, light fittings and any smoke alarm system are fitted and connected once plastering is complete and dry.
5 Testing and certification
The whole installation is inspected and tested, and you receive an Electrical Installation Certificate together with notification to building control.
How Disruptive Is It?
Honestly, it is one of the more invasive jobs in a house. Cables have to reach every accessory, which means lifting floorboards, chasing channels into plaster and drilling through joists and studwork. Expect dust, expect walls to need patching and redecorating afterwards, and expect the power to be off for periods.
Most properties are done in phases so the house stays habitable, typically completing one floor before moving to the next and keeping at least one working circuit live. Even so, many homeowners choose to move out for the first fix week if that is practical. Timescales run from around five days for a small flat to three weeks for a larger house.
The making good question
Plastering and decorating after a rewire is a substantial part of the total effort, and it is the element most often left out of cheap quotes. Clarify at quotation stage whether chased walls will be filled and skimmed ready for decoration, or simply filled roughly. We set out exactly where our work ends and what condition surfaces will be left in, so there is no argument about it later.
Does the Work Have to Be Certified?
Yes. Replacing a consumer unit and installing new circuits are notifiable works under Part P of the building regulations, which means they must be either carried out by a registered competent person who self certifies and notifies, or notified to building control in advance. You should receive an Electrical Installation Certificate and a building regulations compliance certificate on completion.
The notification requirement itself sits within the building regulations, and the routes to approval are explained on the government building regulations pages.
Keep both documents. They are what a buyer’s solicitor asks for on sale, what a landlord needs for compliance, and what an insurer may ask about after a claim. Guidance on the requirements and on finding registered electricians is available from the Electrical Safety First charity.
What Drives the Cost?
Property size sets the baseline because it determines cable runs and accessory counts, but construction type moves the figure much further. A suspended timber floored house with accessible voids and stud partitions is quick to cable. Solid floors, lath and plaster ceilings, thick masonry internal walls and concrete floors all mean far more cutting, chasing and making good for the same number of circuits.
The specification you choose matters too. A straightforward replacement of like for like circuits sits at one end. Adding data cabling, extra sockets in every room, external supplies for a garden building, provision for a vehicle charger and a smart lighting system sits at the other, and each addition brings its own cable run. Whether the property is occupied also affects programme length and therefore labour.
Frequently Asked Questions
How old does a house have to be to need rewiring?
There is no age threshold. Condition decides it. Many properties wired in the 1980s and 1990s remain in good order and need only a consumer unit upgrade, while some 1960s installations have already been partially replaced. An EICR gives you the actual condition of your installation rather than an assumption based on the build date.
Can I live in the house during a rewire?
Usually yes, if the work is phased. Electricians normally complete one floor at a time and keep a temporary supply available for a kettle, fridge and a few lights. It is dusty and inconvenient, and if you have very young children or work from home you may find a week away during first fix easier than the alternative.
Will I need to redecorate afterwards?
Almost certainly. Cables run in chases cut into plaster, and while those chases are filled and made good, the finish will need painting. Ceilings that have been accessed for lighting circuits often need attention too. Budgeting for decoration as part of the project rather than as a surprise afterwards avoids disappointment.
Do I need a rewire to install a car charger?
Not usually. A charger needs a dedicated circuit with suitable protection and an adequate main supply, which many existing installations can accommodate after assessment. What matters is the condition of the earthing arrangement, the spare capacity at the consumer unit and the main fuse rating, all of which an electrician checks before installation.
What is the difference between an EICR and a rewire quote?
An EICR is an inspection that reports the condition of what exists, with coded observations. A rewire quote is a price to replace the installation. You want the EICR first, because it tells you whether a rewire is justified at all, and it gives any electrician quoting the same factual starting point.
Are old fuse boxes actually dangerous?
An old rewireable fuse box is not inherently dangerous, but it lacks residual current protection, which is what disconnects a circuit quickly enough to protect a person from electric shock. That absence is why consumer unit replacement is so often recommended, and it can frequently be done as a standalone upgrade without a full rewire.
Finding Out Where You Stand
Rewiring is a significant project, so it should never be recommended on a hunch. We start with a proper inspection and test, explain what the codes mean in plain terms, and then set out whether targeted remedial work or a full replacement is the right answer for your property. You can see the range of electrical work we handle on our services overview.
Quality Building and Contracting Services
Omnis Developments, Liverpool and the North West