Full House Rewiring in London: Costs, Process & When You Need One 2025

The most reliable way to determine whether a London property needs a full rewire is to commission an EICR (Electrical Installation Condition Report) from a qualified electrician registered under a Part P Competent Persons Scheme (NICEIC, NAPIT, ELECSA). An EICR inspects and tests the existing electrical installation against the current edition of BS 7671 (the IEE Wiring Regulations) and classifies faults as C1 (Danger present — requires immediate remediation), C2 (Potentially dangerous — requires urgent remediation), or C3 (Improvement recommended). An EICR that returns multiple C1 and C2 codes is a strong indicator that a full rewire is needed. Common signs of an electrical installation in need of rewiring: Old consumer unit (fuse board): a consumer unit with rewirable fuse wire (where blowing a fuse requires threading new wire) or an old ceramic fuse board is a strong indicator of a pre-1980s installation. Modern consumer units use Miniature Circuit Breakers (MCBs) and Residual Current Devices (RCDs) or RCBOs for each circuit. A modern consumer unit is required by BS 7671 and the absence of RCD protection is a C2 fault on an EICR. Rubber or fabric-insulated wiring: pre-1960s electrical installations used rubber-insulated wiring (with a fabric outer sheath, often described as 'black and red' or 'rubber TRS cable'). Rubber insulation degrades with age, becoming brittle and cracking — creating a risk of short circuit and fire. The presence of rubber-insulated cables in a London property is a clear indicator that the entire installation needs replacement. No earthing (or inadequate earthing): older London properties may have 'two-wire' installations without an earth conductor, or with inadequate earthing continuity. Proper earth fault protection is fundamental to electrical safety — an installation without proper earthing is dangerous. Metal accessories: round-pin sockets (pre-1962), old-style square-pin sockets with no shutters (pre-1970s), and unfused spur points from a ring main indicate an old installation. Single-socket outlets: modern electrical installations provide sufficient socket outlets to avoid multiple plug adaptors and extension leads — which are a fire risk. A Victorian terrace renovation that retains the original single-socket-per-room configuration is an indicator of an old system. Fuses that blow repeatedly or unexplained power cuts: repeated failure of fuses or MCBs without an obvious cause indicates a wiring fault.

A full house rewire involves the complete replacement of all electrical cables, accessories (sockets, switches, ceiling roses), and the consumer unit throughout the property, from the meter tails and main earth connection at the distribution network operator's cut-out through all circuits to all accessories. The scope of a full rewire: Consumer unit: new dual RCD or RCBO consumer unit (Wylex, Hager, or equivalent) with MCBs for all circuits, installed in an accessible and ventilated location (usually in the cupboard under the stairs or hallway). All circuits: all existing circuits are disconnected, cables removed (where accessible), and new circuits installed. Typical circuit types in a London 3-bedroom Victorian terrace: (1) Ring main circuits (2-3) for power sockets (each ring covers one floor or area); (2) radial circuits for kitchen appliances (cooker, fridge, dishwasher, washing machine — each on a dedicated radial with a suitable MCB); (3) lighting circuits (one per floor, typically; LED circuits for whole-house LED lighting may use smaller cable than incandescent lighting circuits); (4) bathroom circuits (electric shower on a dedicated 40A or 50A radial if installed; fan and heated towel rail on a dedicated bathroom circuit); (5) outdoor sockets and garden lighting circuits (separate RCD protection required); (6) EV charge point circuit if applicable. New cable routes: new cables are typically run in the wall chases (channels cut in the plasterwork) or under floor boards. In a property being renovated and replastered, the rewire is ideally done at first-fix stage — cables are chased into the newly prepared walls before the first coat of plaster, which provides the cleanest finish and least disruption. In an occupied property not being replastered, cables may need to be run surface-mounted (in plastic trunking) or partially concealed under floorboards — less neat but avoiding full replastering. Accessories and new positions: new sockets, switches, and ceiling roses are installed at all new and existing outlet positions. The rewire is an opportunity to review and update the socket layout — increasing the number of double sockets in all rooms, adding USB-A/C integrated sockets, and ensuring all sockets are in the correct positions for the furniture layout. Testing and certification: the completed installation is tested to BS 7671 by the installing electrician and an Electrical Installation Certificate (EIC) is issued. The EIC is submitted to Building Control under Part P of the Building Regulations. The EIC is an important legal document confirming the installation's compliance — keep it with the property deeds.

Full house rewire costs in London vary primarily by property size (number of bedrooms and circuits), the accessibility of existing cables for removal, and whether the property is vacant or occupied during the works. Indicative rewire costs for London properties (2025, all-in including materials, labour, consumer unit, testing, and EIC): 1-bedroom flat (studio to 1-bed, up to 50 sq m, typically 6-8 circuits): £2,500-£4,500. 2-bedroom flat or small Victorian terrace (2-bed, up to 70 sq m, 8-12 circuits): £3,500-£5,500. 3-bedroom Victorian terrace (3-bed, 80-120 sq m, 10-16 circuits): £5,000-£8,500. 4-bedroom Victorian or Edwardian terrace (120-160 sq m, 14-20 circuits): £7,000-£12,000. 5-bedroom detached house or large Victorian terrace (160 sq m+, 18-26 circuits): £9,000-£16,000. Factors that increase rewire costs: Property occupied during the works: cables must be concealed without full replastering — requires more careful routing and surface-mounted trunking. Add 20-30% to a vacant-property rewire cost. Smart home integration (smart switches, EV charger, whole-house audio): add £2,000-£8,000+ depending on the extent of smart home specification. Basement or cellar: additional circuits and more complex cable routing. Add £500-£2,000. Three-phase supply (rare in London residential): specialist requirement, adds significant cost. The rewire and renovation programme: in a London Victorian terrace being renovated, the rewire is most efficiently carried out in two stages — first fix (cables run and chased in, back boxes fitted) at the start of the project before plastering; second fix (sockets, switches, consumer unit, ceiling roses, testing and commissioning) after the plastering and decoration are complete. Running the rewire in tandem with the renovation (rather than as a separate project) reduces disruption, avoids the need to make good plasterwork twice, and allows the socket layout to be planned to suit the final furniture arrangement.

All electrical installation work in a dwelling house in England (with limited exceptions for like-for-like replacements of accessories) is notifiable under Part P of the Building Regulations. Notifiable electrical work must be: carried out by a Part P Competent Person (registered under NICEIC, NAPIT, ELECSA, or another approved scheme) who self-certifies the work; or notified to Building Control before commencement and inspected by Building Control on completion. In practice, the vast majority of domestic electrical work in London is carried out and self-certified by NICEIC or NAPIT registered electricians. The registration database for NICEIC, NAPIT, and ELECSA contractors is searchable online — always verify a contractor's registration before appointing them for notifiable electrical work. The Electrical Installation Certificate (EIC): the EIC is a legal document issued by the installing electrician confirming that the installation has been installed and tested in compliance with BS 7671. The EIC contains: the installer's details and Part P registration number; a description of the installation; the results of all protective conductor continuity tests, insulation resistance tests, polarity tests, and RCD tests. Keep the EIC permanently with the property deeds. A house rewire without an EIC cannot be properly certified and may create problems on resale (buyer's solicitors routinely request EICs for recent electrical work). Choosing an electrician for a London rewire: Part P registration is a minimum qualification — verify the registration on the relevant scheme website (niceic.com, napit.org.uk, elecsa.co.uk). Ask for references from recent full rewire projects. Check insurance (Employers Liability and Public Liability insurance are standard requirements for qualified electricians). For a full house rewire, a single electrical contractor is preferable to a self-employed spark for the scale and coordination of the project — a multi-person firm can complete a typical Victorian terrace rewire in 3-5 days (first fix + second fix combined in one visit, with replastering by the main contractor between).