What Is Rewiring? What Actually Happens During a House Rewire

Rewiring means stripping out a property's old cables, sockets, switches and consumer unit and installing a new system, tested and certified to BS 7671. It isn't one job but a sequence of stages that touches nearly every wall in the property, which is why our house rewiring service starts with a survey rather than a price over the phone. Below is what rewiring means in practice, when a home needs it, what happens day to day, and why it always has to go through a qualified electrician.

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What is rewiring?

Rewiring is the process of removing the existing electrical wiring, sockets, switches, and consumer unit from a property and installing a brand new system in their place. It brings the electrics up to current UK regulations, restores safety in older homes, and gives the installation the capacity to handle modern loads.

Every UK home has cables running through the walls, under the floors, and across the ceilings, feeding power to sockets and lights and connecting everything back to the consumer unit (the modern version of a fuse box). Over decades, those cables, fittings, and protective devices wear out. Insulation breaks down. Older technology like rewireable fuses stops meeting current safety standards. The system loses the ability to cope with contemporary appliances, EV chargers, and smart home tech. A rewire replaces all of that.

When does a house need rewiring?

Many electricians use 25 to 30 years as a rough rule of thumb, but it is not a fixed rule: Electrical Safety First says there are no set guidelines for when a property should be rewired. Some installations last longer. Others fail much sooner. The decision is usually triggered by visible warning signs and the findings of an Electrical Installation Condition Report (EICR).

The clearest signs your house needs rewiring include:

• The consumer unit trips often without an obvious cause

• Cracking, buzzing, or humming from sockets or the fuse board

• A burning smell with no identifiable source

• Discolouration or scorch marks around sockets and switches

• Sockets that feel warm to the touch

• Lights that flicker or dim when appliances switch on

• Old cables: cloth, rubber, lead-sheathed, or two-core lighting circuits with no earth

• Round-pin sockets instead of three-pin

• A wooden-backed fuse board, cast-iron switches, or unlabelled circuits

• An EICR returned with C1 or C2 codes

If you've moved into a property and don't know its electrical history, an EICR is the starting point. It's a formal inspection that records the condition of the installation, codes any faults, and tells you whether a full or partial rewire is needed. Electrical Safety First recommends an inspection at least every 10 years for an owner-occupied home.

What happens during a house rewire?

A rewire isn't one continuous job. It runs in stages, with other trades involved in the middle. Knowing the order helps you plan around it.

1. Survey and planning

The electrician walks the property with you, marks socket and switch positions, agrees the specification (number of sockets, lighting circuits, dimmers, USB points, EV charging, smart home wiring), and writes up a detailed quote. This is also the moment to flag any extra wiring for future use, like Cat6 cabling for hardwired internet or extra circuits for an outbuilding.

2. First fix

The first fix is the loud, dusty stage. Floorboards come up, walls get chased out, joists are drilled. The old wiring is removed and new cables are run from each socket, switch, and light fitting back to the consumer unit. New back boxes are fitted at every accessory position. By the end of first fix the cables are all in place but nothing is connected and energised yet; the split between first fix and second fix is what lets other trades work in between.

3. Plastering and making good

The chases in the walls have to be filled and made good before second fix. This is usually a separate trade, and in houses with floor voids and stud walls it is sometimes possible to rewire without removing plaster along most routes. The plaster needs time to dry, which is why a rewire schedule tends to span a few weeks of elapsed time rather than days, even though the electrical work itself is faster.

4. Second fix

Once the walls are made good, the electrician returns to fit faceplates on sockets and switches, hang light fittings, terminate every circuit at the new consumer unit, and energise the installation. This is the satisfying part of the job. Things start to work.

5. Testing and certification

Every new installation has to be inspected and tested under BS 7671 (the IET Wiring Regulations) before it can be signed off. Insulation resistance, earth continuity, RCD operation, polarity, and ring final circuit tests are all carried out. The electrician issues an Electrical Installation Certificate (EIC) at the end, which is your record of what was installed and how it tested. Because a rewire is notifiable, you should also receive a Building Regulations compliance certificate.

Full rewire vs partial rewire

Not every property needs the full job. The choice usually comes down to the condition of the existing system and how the EICR has coded any faults.

A full rewire replaces every cable, every accessory, and the consumer unit. It's the right call for older houses with end-of-life wiring, properties about to undergo significant renovation, and any home where the EICR has flagged the system as unsatisfactory across multiple circuits.

A partial rewire replaces only the affected circuits or rooms. It tends to make sense when:

• Only one or two circuits have failed

• A specific room (often a kitchen or bathroom) has been added or recently renovated

• The rest of the wiring is reasonably recent and in good condition

• Budget is tight and the work can be phased over time

• The consumer unit is failing but the cabling itself is sound

In our experience, partial rewires are common in 1980s and 1990s houses where the consumer unit and kitchen need updating but the rest of the property is still serviceable. Older Victorian and Edwardian terraces with cloth or rubber-insulated cabling almost always need the full job.

How long does a rewire take?

A full rewire of a typical three-bedroom UK house takes around 6 to 10 working days on site for the electrical work, plus time for plastering and drying. Our guide to how long it takes to rewire a house breaks that down by property size and explains what adds days.

What does it cost?

The cost to rewire a house varies widely with property size, specification, and how much access there is to existing cable routes. National cost guides put a typical three-bedroom UK house rewire at around £4,450 to £8,000 (Checkatrade, June 2026), with larger or more complex properties running higher. A partial rewire of a single room costs a fraction of that, depending on how many circuits it touches. A proper written quote based on a site visit is the only reliable number. Be wary of off-the-cuff figures from anyone who hasn't seen the property.

Why a qualified electrician is non-negotiable

A house rewire is not a DIY job, and it isn't a job for a general handyman. Domestic electrical work falls under Part P of the Building Regulations, which requires notifiable work (a new circuit, a consumer unit replacement, or work in a bathroom's zones) to be either self-certified by a registered competent person or notified to Building Control before work starts and signed off by them. Part P is one of several regulations that apply to rewiring, alongside BS 7671.

The simpler route is to use an electrician registered with a Competent Person Scheme. They can self-certify under Part P and issue the Electrical Installation Certificate at completion. Without one, you'll have problems if you come to sell the property, need to claim on your insurance after an electrical incident, or face a Building Control challenge.

As electricians serving Wolverhampton and the West Midlands from Shifnal, we're registered to self-certify every job ourselves. On electrical installations the paperwork matters as much as the work itself, and a missing or incorrect certificate can cause more trouble than the wiring it covers.

In Shropshire, West Midlands or nearby? Get an exact quote to rewire your property ➜

Rewiring a business, or a home you're still living in

A rewire in an occupied home or a working business is planned around the people using it, and that planning decides how disruptive rewiring is in practice. We agree which circuits must stay live each night (usually the fridge, a few sockets and the lights in the rooms you sleep in), then work room by room or floor by floor so part of the building always has power. Dust sheets go down, and cleaning up at the end of each day is part of the job.

Commercial premises add items a house rarely needs. That can mean three-phase supplies for machinery, emergency lighting, integration with a fire alarm system, extra circuits for desks or equipment, and spare capacity for the business to grow. Planning those at survey stage costs far less than adding them after the walls are finished.

Whatever the property, the paperwork at the end should include the Electrical Installation Certificate and, for notifiable work in a home, confirmation that it has been notified to Building Control through the electrician's registration scheme. Keep both with the deeds; a buyer's solicitor or your insurer may ask for them.

Get a clear assessment before any work starts

Every property is different, and the only reliable way to know what your home actually needs is a proper inspection. If you're in the West Midlands and want a straight answer on whether your home needs a full rewire, a partial rewire, or just remedial work on specific circuits, get in touch about house rewiring in Wolverhampton and across the wider region. We'll arrange a site visit, walk through the property with you, and tell you plainly what the work involves.