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How Do Electricians Rewire A House? - Complete Guide

Rewiring a house should always be done by a qualified electrician. As an electrician or tradesperson, you're aware that this is a significant project requiring meticulous planning. With regulations, tools, and supplies frequently changing, there may be elements of the job you might overlook, especially if rewiring isn't something you do regularly.

This guide by your trusted electrician in London, TNS Electrical Solutions, aims to provide you with a comprehensive understanding of what to consider when rewiring a house and the best practices to follow. You’ll discover the signs indicating a house needs rewiring and understand what the process involves. Additionally, you'll learn about Electrical Installation Condition Reports and current wiring regulations, as well as the essential supplies and tools needed for the job.


Table of Contents


Our Electrician London Tips: Signs a House Needs Rewiring

If a home hasn't been rewired in the last 25-30 years, it likely needs an upgrade to meet current standards. Here are some common signs indicating a house may need rewiring:

  • The consumer unit trips frequently, and fuses or bulbs blow regularly.

  • You hear crackling or buzzing noises from electrical sockets.

  • The wiring is covered in black rubber, fabric, or lead.

  • There are signs of burning, like discolouration around plugs and sockets or a burning smell.

  • Lights flicker constantly, and bulbs need replacing often.

  • Switches are made of cast iron.

  • The consumer unit lacks labelling.

  • The consumer unit has a wooden back.

  • Sockets are broken or cracked.

  • Sockets have rounded plug entries instead of 3-pin entries.

  • There are fewer than two plug sockets in each room.

  • Plugs get excessively hot.

It's always recommended to have this work done by a qualified electrician.

What Does Rewiring a House Involve?

Rewiring a house generally means replacing old wiring and installing new electrical components. Here’s what the process entails:

  • Electrical cables are replaced, and a new consumer unit is installed.

  • New cabling is fitted into the walls and beneath the floors.

  • Back boxes on all switches and sockets are replaced with new ones.

  • Power and lighting circuits are rewired.

  • Telephone and TV aerial sockets are rewired.

  • Switches, sockets, and light fixtures are added or moved if needed.

  • Cabling for new technology, such as speakers, CCTV cameras, and automated lighting, is added if required.

This wiring work is usually divided into two stages, known as 'fixes'.

First Fix

The first fix stage involves all the work needed on hidden cabling before plastering begins. This typically includes cutting chases and installing cabling into the walls, fitting new back boxes for switches and sockets, rewiring power, heating, and lighting circuits, and rewiring phone and TV aerial sockets. Additionally, this stage covers adding cabling for new technology like burglar alarms, CCTV cameras, smoke detectors, doorbells, and outdoor lighting.

When cutting chases into walls, it's crucial to follow these guidelines to comply with electrical regulations and maintain wall stability:

  • A vertical chase must not be cut deeper than one-third of the total wall thickness.

  • In a cavity wall, a vertical chase must be no deeper than one-third of the thickness of the skin it’s placed in.

  • No chases, whether horizontal or vertical, should be made back-to-back.

  • A horizontal chase must not be cut deeper than one-sixth of the total wall thickness.

  • In a cavity wall, a horizontal chase must be no deeper than one-sixth of the thickness of the skin it’s placed in.

  • Chases must go from A to B in a straight line, either vertically or horizontally. Diagonal chases are not permitted.

Second Fix

The second fix stage begins once all plastering is completed and the walls are finished. This stage typically includes wiring in the faceplates on switches and sockets, installing light fittings, and connecting items such as cookers, extractor fans, electric showers, and heating controls. Finally, everything is connected to the consumer unit and tested to ensure all components are live and functioning properly.

What is an Electrical Installation Condition Report (EICR)?

An Electrical Installation Condition Report (EICR) is a document produced after inspecting a property's electrical systems. The purpose of an EICR is to identify any damage or wear that could cause electric shocks, high temperatures, or other safety hazards. It also highlights any wiring that does not comply with the Institution of Engineering and Technology (IET) regulations and serves as an important record for future inspections.

There are two types of EICR:

Visual Condition Report: This report is suitable for properties that have been fully tested recently. It involves a visual inspection to confirm that the electrics are safe to use until the next inspection. It checks things like ensuring sockets aren't overloaded and appliances have Residual Current Device (RCD) protection.

Periodic Inspection Report:  This comprehensive report includes a full inspection and testing of a property's electrics, including circuitry hidden behind walls. It is recommended every 10 years for private homes and every five years for rental properties.

When homeowners or landlords receive their EICR, they must address any faulty or outdated wiring highlighted in the report. This ensures the property complies with the latest UK electrical wiring regulations and that the electrical installation is safe.

What are the Wiring Regulations?

The UK's current wiring regulations, known as the 18th edition, are the national standard for all domestic electrical wiring work. These regulations set the rules for the installation of fixed cabling within a property to ensure safety.

The regulations mandate that all work must comply with Approved Document Part P of the Building Regulations and follow the guidelines of BS7671, often referred to as the IET wiring regulations. These cover the design, installation, inspection, testing, and certification of electrical wiring. Every piece of wiring work must be completed to this standard to ensure safety and compliance.

Top Rewiring Supplies and Tools

This section highlights some of the top tools and equipment for electricians. It covers the essential products and supplies every electrician needs to complete a rewiring job competently and efficiently.

Cable and Cable Management

Cable is, naturally, one of the most crucial supplies for any rewiring job. There are many types of cable available in various lengths. For rewiring, it’s best to use cable on drums, available in lengths from 25 to 100 metres. Drums make it easier to pull the wires without tangling, saving you time on the job.

Don’t forget cable management products like trunking, conduit, cable covers, and protectors. These help keep your wiring orderly and uncluttered, providing an important safety measure, especially where exposed cables could cause a trip hazard.

Positioning and Cutting Tools

Having a variety of positioning and cutting tools will make your work smoother and faster. The best tools to use are VDE tools. VDE is an internationally accredited testing and certification institute. Tools with VDE certification have insulated handles to prevent electric shock injuries, and their red handles ensure easy identification among other tools.

Essential positioning and cutting tools include long-nose pliers, side cutters or snips, wire strippers, and crimps.

TNS Electrical Solutions electrician working in Chelsea, London.
Stay safe!


Insulated screwdrivers are essential for every electrician. They’re crucial for wiring electrics and mounting faceplates on switches and sockets. It's best to have a wide range of sizes to cover all the different screws you might encounter. As with other tools, use VDE screwdrivers which are insulated up to 1000V AC and 1500V DC to protect against electric shock and arcing.

Switches, Sockets, and Back Boxes

Every house rewire involves replacing back boxes during the first fix. To save time and money, it’s important to plan and buy the correct type of back boxes to suit the job’s requirements, depending on where the back box is going and the depth of the device being installed.

During the second fix, you'll fit new switches and sockets. These come in a wide range of types, colours, styles, and finishes, allowing them to add a stylish touch to a room. Your customers may want to choose these themselves.

Grid and Modular Wiring

Grid and modular wiring products allow you to create bespoke combinations of switches and sockets since all components are sold separately. You buy a grid plate and faceplate, then any combination of switches, sockets, blanking plates, fused spurs, and fixed outlet modules. Everything clicks together.

This means you can conveniently control power and lighting for any room from one location. From an efficiency perspective, it allows you to wire just one plate instead of multiple ones, saving you time.

Electrical Testers

Electrical testers are crucial tools for safety while carrying out electrical work. They also let you check that the wiring is installed correctly and that all test readings meet IET regulations.

There are various types of electrical testers. For example, a socket tester checks if a socket is dead or wired correctly. A voltage tester detects the presence or absence of electricity in a circuit. A continuity tester checks if an electrical path can be made between two points, and a resistance tester ensures that a cable is part of a continuous circuit. Multifunctional testers combining two or more of these tools are also available.

Torch on light switch: job by TNS Electrical Solutions in Fulham, London.
Shine bright!

Head Lamp / Torch

When rewiring, you’ll often work in dark spaces like lofts and cupboards or after dark, especially in winter. Since rewiring a house involves turning off the electricity, a good battery-powered headlamp or hand torch is essential. A head torch is particularly useful as it allows hands-free working.

Wall Scanner

A wire tracer or scanner is another handy tool that helps locate wires behind walls and beneath floors. It tells you the direction of the circuit and detects circuit breakers and fuses, saving you time when locating existing wiring.

Hammer Drill

A hammer or SDS drill is essential for cutting chases into masonry walls and brickwork. As you’ll have no electricity while working, a battery-powered drill is necessary. Look for versions with long battery life or two batteries to avoid running out of power midway through the job.

Fish Tape Or Rods

On a rewiring job, cables should be installed before being hidden behind plasterboard. However, extra cables may sometimes be needed after the plasterboard is in place. Fish tape (or rods) is useful in these situations. It’s a coil of rigid steel with a hook on one end, used to fish cables through walls or across ceilings and to run cables through conduit.

A Consumer Unit

A consumer unit is the control centre for the house’s power supply, designed to prevent electric shocks and fires. It’s an essential piece of equipment that should always be replaced during a rewiring job. With many brands and sizes available, it should be easy to find the right product for your needs.

Other Supplies?

Besides the main items mentioned, various other supplies will come in handy on a rewiring job. Electrical screws are perfect for installing sockets with a thread that doesn’t loosen. Electrical tape is useful for insulating wiring to prevent shocks or fires. Cable ties help keep wires neat and tidy.

Personal protective equipment (PPE) is also important. Use goggles and gloves with good grip when chasing out walls. Don’t forget basics like a pencil, tape measure, and spirit level to mark out the positions of switches and sockets.

London electrician's work: Light switch.
Light Switch

What to Consider When Rewiring a House?

Plan the Position of Lights, Switches, and Sockets

Careful planning is crucial for a successful rewiring job. Before starting, map out where everything will go. Work on a room-by-room basis, deciding where every light, switch, socket, and other electrical points such as smoke detectors, speakers, security lights, and cameras will be located. Doing this planning upfront will save you from making costly and time-consuming changes later in the project.

Project Timings

Rewiring is typically done in two stages. The first fix stage occurs when floorboards are pulled up, and walls have no plasterboard or channels have been chased out for cabling. This is when all hidden wiring is exposed, old wiring and components are removed, and new cabling is installed.

The second fix stage takes place after the plasterboard is replaced and the walls are made good. This is when you install all external electrical components, such as switches, sockets, and light fittings.

Future-Proofing Your Home

With the increasing use of technology in homes and the growing popularity of smart home devices, it’s important to consider future needs during a rewiring project. Think about how the homeowner’s requirements might change over the next 10 years. For example, consider the current number of sockets and how many more may be needed to meet future demand.

Smart Home Wiring

If the home doesn’t already have smart home technology, this is an ideal time to consider it. Setting up wiring for smart products like CCTV cameras, doorbells, and heating systems now will save time, money, and disruption later. As smart home devices rely on the internet, also consider the internet cabling. Installing additional ethernet connections will provide faster internet access and accommodate future demands.

Official Part P Certification

After completing a rewiring project, you must provide the homeowners with an official certificate confirming that the work meets Part P of the Building Regulations. To issue this certificate, you must be registered with one of the Government-approved Part P schemes.

Rewired Houses in London: Case Studies by TNS Electrical Solutions

TNS Electrical Solutions has successfully completed numerous rewiring projects, ensuring safety and efficiency for their clients. Here are a couple of recent case studies with feedback from happy clients:

Google Maps: Vanston Pl, London
Vanston Pl, London

Vanston Pl, London SW6 1AP, near Vue Cinema London - Fulham Broadway

The team at TNS Electrical Solutions rewired this property, replacing old wiring and upgrading the electrical system to meet current standards. The project included installing new consumer units, updating all switches and sockets, and ensuring compliance with the latest wiring regulations.

Kylie, Homeowner: "TNS Electrical Solutions' electrician in London did a fantastic job rewiring our house. Their professionalism and attention to detail were exceptional. Highly recommend!"

Google Maps: Wardo Ave, London SW6 6RB, near Craven Cottage
Wardo Ave, London SW6 6RB, near Craven Cottage

Wardo Ave, London SW6 6RB, near Craven Cottage on Stevenage Rd, London SW6 6HH

In this project, TNS Electrical Solutions carried out a complete rewire, including the installation of smart home wiring for future-proofing. They added new cabling for CCTV cameras and automated lighting, ensuring the home's electrical system is equipped for modern technology.

Kel, Homeowner: "We are extremely pleased with the rewiring work by TNS Electrical Solutions. They were efficient, thorough, and left our home neat and tidy. Excellent service!"

FAQs on Rewiring a House

Can I legally rewire my house?

Yes, you can legally rewire your house, but it's essential to follow the regulations. In the UK, any significant electrical work, including rewiring, must comply with Part P of the Building Regulations. This ensures that the work is safe. While you can do the work yourself, it must be inspected and certified by a qualified electrician. However, due to the complexities and risks involved, it is strongly recommended to hire a professional.

Does a 30-year-old home need rewiring?

A house that is 30 years old might need rewiring, especially if the wiring has not been updated. Over time, wiring can deteriorate and may not meet current safety standards or handle the electrical load of modern appliances. Signs that rewiring is needed include frequent tripping of the circuit breaker, flickering lights, or a burning smell from sockets. It’s best to have an Electrical Installation Condition Report (EICR) conducted by a qualified electrician to assess the condition of the wiring.

How long does it take to rewire a house on average?

The time it takes to rewire a house can vary based on the size of the property and the complexity of the job. Generally, it can take anywhere from a few days to two weeks. The process involves two stages: the first fix, where new wiring is installed before plastering, and the second fix, where all the final connections are made after the plastering is done. Factors like the number of circuits and the accessibility of existing wiring also affect the duration.

How often should a house be rewired?

Typically, a house should be rewired every 25-30 years. However, this can vary depending on the condition of the wiring and the electrical demands of the household. Regular inspections, such as those provided by an EICR, can help determine if a rewire is necessary sooner. It's also important to update wiring if you’re undertaking major renovations or if the current system cannot support new appliances and technologies.

More for information or help, please contact our electrician in London at

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