A full house rewire is one of the biggest electrical jobs in domestic work. This guide explains when a rewire is needed, what the process involves from first fix to second fix, how long it takes, what it costs, and how homeowners can prepare for minimal disruption.
Free for 7 days · No charge until day 8 · Cancel anytime · Used by 1,000+ UK electricians
Written and reviewed by Andrew Moore, founder of Elec-Mate, against BS 7671:2018+A4:2026, IET Guidance Note 3 and the IET On-Site Guide.
1,000+
UK electricians
“Replaced three separate apps with Elec-Mate. Certs, quotes, and scheduling all in one place.”
Daniel Palmer — DP Electrical
Not every old property needs a complete rewire. The age of the wiring alone is not a reliable indicator — PVC-insulated cable installed in the 1970s can still be in excellent condition if it was installed correctly and has not been subjected to damage, overheating, or moisture. The condition of the insulation and connections matters more than the age.
However, there are clear signs that a rewire is needed or should be seriously considered:
Properties built before the 1960s often have rubber-insulated cable (VIR — vulcanised india rubber) or lead-sheathed cable. Rubber insulation degrades over time, becoming brittle and cracking. When disturbed — even by normal thermal cycling — the insulation can crumble away, exposing bare conductors. Lead sheaths can corrode, particularly in damp conditions. If the property has this type of cable, a rewire is strongly recommended even if it appears to be functioning correctly, because the insulation will continue to deteriorate and the risk of faults increases with every year.
A rewirable fuse board with porcelain or Bakelite fuse holders indicates an installation that has not been updated in decades. While the fuses themselves can provide overcurrent protection, there is no RCD protection, the fuse wire can be replaced with the wrong rating, and the board is likely a plastic or wooden enclosure. A consumer unit change alone may not be sufficient if the wiring behind the board is also in poor condition.
Very old wiring systems used only live and neutral conductors with no separate earth (CPC — circuit protective conductor). Without an earth, there is no path for fault current to flow, which means protective devices cannot operate under an earth fault condition and metallic parts of accessories and appliances cannot be earthed. This is extremely dangerous and is invariably classified as C1 (Danger Present) during an EICR.
An Electrical Installation Condition Report (EICR) that returns multiple C1 (Danger Present) or C2 (Potentially Dangerous) observations across different circuits indicates systemic deterioration. If the insulation resistance readings are consistently low (below 1 MΩ) across multiple circuits, if there are loose connections throughout, or if the wiring does not meet basic safety standards, a full rewire is the most cost-effective and safest solution — patching individual faults in an installation that is failing throughout is rarely worthwhile.
Flickering lights, burning smells from sockets or switches, warm switch plates, discoloured or scorched outlets, tripping fuses or RCDs, and electric shocks from appliances or switches are all symptoms of wiring faults that may indicate the need for a rewire. Any of these should be investigated by a qualified electrician immediately.
Every key change in the 2026 amendment on one page. AFDDs, TN-C-S protection, new schedule columns, model forms. Pinned on your van dash.
A full house rewire replaces all the cables, accessories (sockets, switches, light fittings), and the consumer unit in the property. The existing wiring is removed and new cable is run throughout the house, with new back boxes and accessories installed. The work is carried out in two main phases: first fix and second fix.
The scope of a rewire typically includes:
Elec-Mate's AI Circuit Designer helps plan the complete circuit layout for a rewire — number of ring finals, radials, lighting circuits…
Try it free for 7 days
First fix is the heavy phase of the rewire. This is where the old cables are stripped out, new cable routes are cut into walls (chased), back boxes are installed, and new cables are pulled throughout the property. First fix is the most disruptive phase — it involves lifting floorboards, chasing plaster, drilling through joists, and working in every room.
The existing wiring is disconnected and removed. Old sockets, switches, and light fittings are taken out. Floorboards are lifted to access the cable routes under the floors. In some cases, old cables are left in place if they are inaccessible (e.g., buried in solid concrete floors) and simply disconnected at both ends.
New cable routes are chased into plaster or brick using a chasing machine or SDS drill. Channels are cut vertically from the back box position to the ceiling or floor level. Horizontal chases are avoided where possible (BS 7671 safe zones require cables in walls to run vertically or horizontally from accessories). Holes are drilled through joists and noggins for cable runs under floors and through walls.
Metal back boxes are fitted into the chased channels at every socket, switch, and accessory position. New cables are run from the consumer unit location to each back box, following the agreed circuit layout. Cables are clipped or supported at regular intervals as required by BS 7671. Junction boxes are installed where needed for lighting circuits.
At the end of first fix, the property will have cables protruding from back boxes in every room, the consumer unit position prepared, and all cables labelled and ready for connection. The property is usually without power during much of first fix — a temporary supply from a neighbouring property or a generator may be arranged for essential use.
Elec-Mate's cable sizing calculator ensures every cable in the rewire is correctly specified.
Try it free for 7 daysSecond fix happens after the plasterer has been in (if needed) and the chases have been filled. This is where the installation comes together — accessories are fitted, circuits are connected at the consumer unit, and the complete testing and commissioning process is carried out.
All socket outlets, switches, light fittings, cooker connection units, spurs, and other accessories are fitted to the back boxes and connected. Light pendants are wired, bathroom accessories are installed, and any specialist items (shaver sockets, cooker isolators, outdoor sockets) are connected.
The new consumer unit is mounted and all circuits are connected to their designated protective devices. The main earth and bonding conductors are connected. The circuit chart is prepared and fixed inside the consumer unit door.
The full testing sequence is carried out on every circuit: continuity of protective conductors (R1+R2), insulation resistance at 500V DC, polarity verification, earth fault loop impedance (Zs), prospective fault current (PSCC and PEFC), and RCD operating times. This is the most time-consuming part of second fix — a 10-circuit domestic rewire can take 2-3 hours to test completely.
The Electrical Installation Certificate (EIC) is completed with all test results, circuit details, and installation information. Part P notification is submitted. The homeowner receives the EIC, circuit chart, and operating instructions for the new consumer unit and smoke alarms.
Elec-Mate's digital EIC form handles rewire certification from start to finish. Enter all test results on site…
Try it free for 7 daysThe duration of a rewire depends on the size of the property, the number of circuits, the ease of access (solid floors vs suspended timber floors), and whether the property is occupied during the work.
4-6 circuits
6-8 circuits
8-12 circuits (most common)
10-16 circuits
These timescales assume one or two electricians working full-time and include both first fix and second fix but exclude plastering. After first fix, a gap of 1-3 days is usually needed for the plasterer to fill the chases and make good. The plaster must be dry before second fix begins (typically 24-48 hours for chase filling). Add the plastering time to the electrical timescales for the total project duration.
Working in an occupied property is slower because rooms must be cleared before work begins, furniture must be protected from dust, and temporary power must be maintained wherever possible. An empty property (e.g., a renovation before moving in) can be significantly faster because access is unrestricted.
16 certificate types, 70+ calculators, RAMS, quoting, invoicing, AI agents, and 46+ training courses — from £6.99/mo.
Start free trialGood planning is the difference between a smooth rewire and a frustrating one. The most common source of delays and additional costs is changes to the specification mid-job — "Can we add a socket here?" or "Actually, I want the light switch on the other wall." Every change after first fix cables have been run means pulling new cable, chasing new channels, and potentially replastering.
Walk through every room with the homeowner before starting work. For each room, agree:
Before starting a rewire, use Elec-Mate's Board Scanner to photograph the existing consumer unit and extract all circuit data automatically.
Try it free for 7 daysA full house rewire is notifiable under Part P of the Building Regulations. This is one of the most significant categories of notifiable work — it involves the complete replacement of the electrical installation.
The certification requirement for a rewire is a full Electrical Installation Certificate (EIC). This is not a Minor Works Certificate (which is only appropriate for small additions or alterations to existing circuits). The EIC must include:
The EIC must be signed by the designer, installer, and inspector. On a domestic rewire, the same electrician typically fills all three roles. The certificate is issued to the homeowner, and a copy is retained by the electrician for at least six years (or as required by the competent person scheme). The Part P notification is submitted through the competent person scheme, which then issues a Building Regulations Compliance Certificate to the homeowner.
A house rewire is inherently disruptive — there is no way around the fact that floors need to be lifted, walls need to be chased, and the power will be off for extended periods. However, careful planning can reduce the impact on the household.
Rather than stripping out the entire house at once, work through one room or one floor at a time. This allows the family to use other parts of the house while one area is being worked on. It takes slightly longer but is far less disruptive for an occupied property.
Keep at least one circuit live (typically the kitchen or a socket circuit on a floor not being worked on) so the household has access to power for essentials — fridge, kettle, phone charging. If this is not possible, a temporary supply from an extension lead to a neighbouring property (with their permission) or a small generator can provide basic power.
If the rewire is part of a larger renovation, coordinate with plasterers, decorators, and any other trades. The typical sequence is: electrician first fix, then plasterer fills chases and makes good, then electrician second fix, then decorator paints. Getting this sequence wrong (e.g., chasing after plastering) creates rework and delays.
Chasing walls creates a significant amount of dust. Use dust sheets to cover furniture, seal doorways with plastic sheeting to contain dust to the work area, and use a dustless chasing machine where possible. Carpet should be rolled back and protected where floorboards are being lifted.
Walk through every room with the homeowner and agree socket, switch, and light positions. Design the circuit layout including ring finals, radials, lighting circuits, and dedicated circuits. Specify the consumer unit, cable sizes, and accessories. Calculate maximum demand for the new installation. Photograph and document the existing installation using the Elec-Mate Board Scanner.
Strip out old wiring, lift floorboards, chase walls for new cable routes, install back boxes, and run new cables from the consumer unit position to every accessory point throughout the property. Label every cable at both ends. Install mains smoke and heat detectors. This phase takes 3-7 days depending on the property size.
Allow the plasterer to fill all cable chases, make good around back boxes, and repair any areas of wall or ceiling disturbed during first fix. Wait for the plaster to dry (typically 24-48 hours for chase filling) before proceeding to second fix. This gap is usually 1-3 days.
Fit all socket outlets, switches, light fittings, and other accessories. Connect all circuits at the consumer unit. Install and connect the SPD. Make up earth and bonding connections. Commission smoke and heat alarms. This phase takes 2-4 days depending on the number of circuits and accessories.
Carry out the full testing sequence on every circuit: continuity (R1+R2), insulation resistance (500V DC), polarity, earth fault loop impedance (Zs), prospective fault current (PSCC/PEFC), and RCD operating times. Verify all test results against BS 7671 limits. Commission all circuits — check every socket, switch, and light operates correctly.
Complete the Electrical Installation Certificate with all design, construction, and test data. Prepare the circuit schedule and fix the circuit chart inside the consumer unit. Submit Part P notification through the competent person scheme. Issue copies of the EIC to the homeowner. Provide operating instructions for the new consumer unit and smoke alarm system.
Verified reviews from the UK App Store.
Elec-Mate is my go to app for business and electrical work. It's feature rich without feeling cluttered. A true all in one app for quotes, certs, calculations, RAMS, EICRs, and more. I use it every day without fail, and it makes my workflow much smoother since I'm not jumping between apps anymore. The price-to-feature ratio is excellent. Any issues I've had, the developer responds within the hour and usually fixes them the same day. 100% recommend.
I've used the app and the web based version for a while now and it's well worth the investment. If you're an apprentice or experienced Spark give it a go, you won't be disappointed.
I've been using Elec-Mate for a while now, and honestly, it's one of the best apps I've ever downloaded. Every aspect of it feels thoughtfully designed, from the clean and intuitive interface to the powerful features that make everything so easy to manage. It's clear that a lot of care and attention went into building this app, and it shows in every detail.
Real feedback from real sparks
“Replaced three separate apps with Elec-Mate. Certs, quotes, and scheduling all in one place.”
Daniel Palmer
Sole Trader · DP Electrical
“I've won two contracts this month because I could turn quotes around same-day with the AI cost engineer.”
Nathan Perry
Electrician · NP Electrical Services
“The study centre got me through my AM2. Mock exams and flashcards are brilliant.”
Jake Pizey
3rd Year Apprentice · Apprentice
Cable sizing, max demand calculator, Board Scanner, EIC forms, and AI Circuit Designer — everything for a rewire in one app. 7-day free trial, cancel anytime.
“Replaced three separate apps with Elec-Mate. Certs, quotes, and scheduling all in one place.”
Daniel Palmer, DP Electrical
From £6.99/mo after trial — less than a coffee a week
We use cookies to improve the app and measure what works. Cookie Policy