Rewiring an Old House: What to Expect, Who to Hire, and What It Costs

The wiring in most British homes built before the 1960s was never designed for the demands of modern life. When a Victorian terrace was built, electricity was a novelty rather than a utility; the wiring that was added later was typically rubber-insulated, runs through a consumer unit that would make a modern electrician wince, and has been patched and extended by any number of subsequent owners with varying degrees of competence.

If your home has a dated fuse board with rewirable fuses, rubber- or lead-sheathed cables visible in the loft or under floorboards, or you find yourself resetting fuses regularly, a full rewire is probably overdue. Here's what to expect.

Signs You Need a Rewire

• Round-pin sockets (original 1950s style) or 15A round three-pin sockets
• A consumer unit (fuse board) with rewirable fuses rather than MCBs (miniature circuit breakers)
• Visible rubber-sheathed or fabric-wrapped cables — particularly in the loft or underflooring
• Scorch marks around sockets or switches, or a burning smell from electrical accessories
• Lights flickering or tripping the circuit breaker regularly
• No RCD (residual current device) protection — your fuse board should have at least one RCD or RCBO protecting sockets and outdoor circuits
• A NICEIC or NAPIT Electrical Installation Condition Report (EICR) grading the installation as "C2" (potentially dangerous) or "C1" (danger present)

What a Full Rewire Involves

A full rewire means replacing every circuit in your home — lighting, ring main, cooker, immersion heater, outdoor circuits — from the consumer unit outward. All existing cables are removed (or, where they're inaccessible, decommissioned and left in situ), new cables are run to every socket outlet, light fitting, and fixed appliance, and a new consumer unit is fitted.

In most homes, cables are surface-run in plastic conduit or, more commonly, "chased" into the plaster in channels cut by a chasing tool (also called a chaser or furring machine). After the cables are run and connected, the channels are filled and replastered. This means a full rewire is a seriously disruptive undertaking — floors come up, walls are chased, and rooms need redecorating afterwards.

A typical three-bedroom semi-detached house takes a two-man team 3–5 days to rewire. Factor in at least 2–4 weeks before you can redecorate after the plasterwork is repaired, more if you need to employ a separate plasterer.

The Cost of a Full Rewire in the UK (2026)

Prices vary considerably by region, house size, and complexity. As a rough guide:

• 1-bedroom flat: £2,000–3,500
• 2-bedroom terraced house: £2,500–4,500
• 3-bedroom semi-detached: £3,500–6,000
• 4-bedroom detached: £5,000–9,000+

These figures are for the electrical work only and exclude any plasterwork repairs, decoration, or remedial carpentry. Add £500–1,500 for plaster repairs in a typical three-bedroom property, depending on the extent of chasing.

Always get three quotes and ask for a written breakdown of the work included. Beware of unusually low quotes — the cheapest electrician is rarely the most cost-effective option when something goes wrong.

Partial Rewires and Consumer Unit Upgrades

If a full rewire is outside your budget, there are partial solutions that address the most critical safety concerns:

• Consumer unit replacement — upgrading from an old fuse board to a modern unit with MCBs and RCDs/RCBOs provides significantly better protection against electrocution and fire. A consumer unit replacement typically costs £400–700 including labour and is far less disruptive than a full rewire.
• Adding RCD protection — an RCD socket adapter (from around £15 at Screwfix) can be plugged into any socket to provide RCD protection for that circuit. It's a stopgap, not a solution, but useful in the short term.
• Replacing specific circuits — kitchen and bathroom circuits carry the highest risk. If the rest of the wiring is in reasonable condition (modern PVC-sheathed cables), replacing these two circuits while leaving others can be a pragmatic first step.

Who to Hire

In England and Wales, all electrical work in kitchens, bathrooms, and outdoors — and any new circuit anywhere in the home — must either be carried out by a Part P-registered electrician (who can self-certify the work) or be approved by the local authority (which involves submitting a building notice and paying an inspection fee). Engaging an unregistered electrician for notifiable work risks problems when you come to sell.

Use only electricians registered with a competent person scheme:

• NICEIC — the main UK electrical contracting body. Their "Approved Contractor" scheme has the highest entry requirements.
• NAPIT — National Association of Professional Inspectors and Testers. Registered contractors must meet specific competency standards.
• SELECT — the scheme in Scotland.

You can check any electrician's registration at niceic.com or napit.org.uk. Ask to see their qualification card and public liability insurance certificate before work begins.

What to Expect During the Work

Day one usually involves the electrician disconnecting the existing supply, removing the old consumer unit, and beginning to trace and remove existing circuits. Expect to be without power for the first day — have torches, a camping stove, and extension cables from a neighbour arranged in advance if you're remaining in the property.

Prepare for disruption. Furniture needs to be moved from walls. Floors may come up in several rooms. Carpets can usually be re-laid, but a full rewire is an excellent opportunity to check the condition of underfloor joists, pipes, and insulation.

The Electrical Installation Condition Report (EICR)

Whether you're rewiring a property you own or buying one with old wiring, an EICR (formerly called a Periodic Inspection Report or PIR) is a thorough test of the installation's safety. It produces a report grading any deficiencies as C1 (danger present), C2 (potentially dangerous), or C3 (improvement recommended). Any C1 or C2 items must be rectified.

An EICR costs around £150–250 for a typical house. Since 2020, landlords in England are legally required to have a valid EICR (no more than 5 years old) for all rental properties. For homeowners, it's simply excellent peace of mind — particularly before buying a property with older wiring.

A full rewire is a significant investment and disruption. But it's one that removes a genuine safety risk, brings your property up to modern standards, and will typically last 25–40 years before anything comparable is needed again. For any property with wiring that's more than 30–40 years old and has never been fully updated, it should be near the top of the improvement priority list.