Contents
Signs That a London Home May Need Rewiring
Age of installation: electrical installations are typically recommended for replacement after 25 to 35 years of service. An installation that has not been updated since the 1980s or 1970s is approaching or past this threshold. Installations from the 1960s or earlier (rubber-insulated wiring, no earth continuity in lighting circuits, round-pin sockets) should be considered for urgent replacement.
Regulatory indicators: round-pin sockets (pre-1947 BS 546 pattern), brown or rubber-sheathed wiring visible in loft or under floorboards, a fuse board with rewirable ceramic fuses (rather than MCBs), no residual current devices (RCDs) on circuits serving bathrooms, kitchens, or outdoor sockets.
Electrical faults: frequent tripping of MCBs, overheating sockets or switches, lights flickering, burning smells, discolouration of socket or switch faceplates.
EICR result: an Electrical Installation Condition Report (EICR) carried out by a qualified electrician will identify any code 1 (danger present — immediate action), code 2 (potentially dangerous — urgent attention), or code 3 (improvement recommended) observations. Significant code 1 or 2 findings, particularly widespread ones, often indicate that rewiring is required.
What a Full Rewire Involves
A full rewire is the replacement of all wiring, circuits, consumer unit (fuse board), sockets, switches, and light fittings throughout the property. In a standard London terrace or flat, the process includes:
1. Isolation and strip-out: the existing consumer unit is isolated and all existing cables in walls and floors are identified and (where practical) removed or abandoned in situ.
2. First fix: new cables are run from the consumer unit position throughout the building. In a Victorian terrace, cables are typically run in surface-mounted conduit (chased into the wall and plastered over) or clipped to joists beneath floors. Running cables beneath floors requires carefully lifting and relaying floorboards.
3. Back boxes: metal or plastic back boxes for sockets and switches are fitted into the wall (chased in) or mounted on the surface, depending on finish preferences and wall construction.
4. Consumer unit installation: a new consumer unit compliant with BS 7671 (18th Edition Wiring Regulations) is fitted. Modern consumer units include both MCBs and RCDs (or AFDDs for some circuits in the latest regulations).
5. Second fix: socket and switch faceplates, light fittings, and accessories are fitted and connected. The system is tested.
6. Certification: the electrician issues an Electrical Installation Certificate (EIC), confirming the installation complies with BS 7671 and has been tested.
Part P Building Regulations
Notifiable electrical work in a dwelling (including new circuits and rewiring) must be carried out by either:
- A qualified electrician registered with a Part P competent person scheme (NICEIC, NAPIT, ELECSA, or similar). The electrician self-certifies the work and notifies the local authority through the scheme.
- A non-registered electrician — in which case the work must be inspected and approved by a building inspector before the consumer unit is re-energised.
For safety reasons, always use a Part P registered electrician for domestic electrical work.
Planning a Rewire Around Other Building Work
A rewire is most cost-effectively done when other building work is also being carried out that requires walls and floors to be opened up:
- Loft conversion: first-fix electrical work for the loft (wiring through ceilings and walls to the floor below) is carried out during the construction phase, when all surfaces are accessible.
- Extension: new circuits to the extension should be integrated with a rewire of the existing property rather than added as a standalone sub-board.
- Refurbishment: stripping rooms back to the structure (removing plaster, lifting floors) for a refurbishment is the ideal time to rewire, because the access is already there and the cost of re-plastering does not need to be duplicated.
Rewiring after decoration is complete means lifting or damaging finishes — which adds cost and time. Where possible, electrical and plumbing first-fix should be the first trades through after demolition and structural work, before plastering.
Smart Electrical Systems
Modern rewires increasingly incorporate provision for smart home systems — additional wiring for multi-room audio, structured data cabling (Cat6 ethernet to each room), HDMI or data outlets for home cinema, and provision for EV charging. This infrastructure is best installed during a rewire when walls and floors are open, as retrofitting it later is expensive. Planning the smart home infrastructure before the rewire starts allows the electrician to incorporate it into the design.
Typical Costs for Electrical Rewiring in London (2026)
- Consumer unit replacement only (no rewiring): £500 to £900
- Partial rewire (one or two floors, or one specific circuit type): £2,000 to £6,000
- Full rewire of a 2-bedroom flat: £4,000 to £8,000
- Full rewire of a 3-bedroom mid-terrace house: £6,000 to £12,000
- Full rewire of a 4-bedroom London terrace with loft conversion: £10,000 to £18,000
- EICR test and report (pre-purchase or landlord compliance): £150 to £350
Want advice on your own project?
Pick whatever suits you. We'll look at what you have (drawings, photos or quotes) and tell you honestly what the next step should be.
Prefer to phone? Call +44 7359 872594.
Important Note
This guide is for general information only. Building regulations, planning rules, and legal requirements change regularly and vary by local authority. Always seek professional advice specific to your project and location. To talk through your own project, book a project review.
Was this guide helpful? Share it:
Have a question about your project?
Message us on WhatsApp or call — we reply during working hours (Mon–Fri 8am–6pm, Sat 9am–2pm).