Rewiring a house: essential certificates and records to keep

Carrying out a full or partial rewire is one of the most disruptive and significant improvements you can make to a property. Because electrical cables, conduits, and back boxes are quickly plastered over and hidden beneath floorboards, the quality and safety of the installation cannot be checked simply by looking at the finished walls. Proper documentation is the only verifiable proof that the work was designed, installed, and tested to national safety standards.

Building Regulations and Part P compliance

In England and Wales, electrical work in domestic properties must comply with Part P of the Building Regulations. Part P is designed to reduce the risk of electrical fires and shocks by ensuring electrical installations are safely designed, installed, inspected, and tested.

Major domestic electrical work is legally notifiable to local authority Building Control. This includes full rewires, adding new circuits, replacing a consumer unit (fuse box), and alterations in specialised locations such as bathrooms or wet rooms. If you use an electrician registered with a competent person scheme (such as NICEIC, NAPIT, or ELECSA), they can self-certify the work and notify Building Control on your behalf. If the installer is not registered, you must notify Building Control directly before work begins so they can arrange inspections.

The core electrical documents you must receive

When a major electrical project is completed, you should receive specific paperwork from your installer and the competent person scheme. Never make a final payment until these documents are in hand or formally arranged.

• Electrical Installation Certificate (EIC): This is the primary technical document issued by the installer under BS 7671 (the IET Wiring Regulations). It confirms the installation meets current safety requirements and includes detailed schedules of inspections and test results for every circuit.
• Building Regulations Compliance Certificate: Issued directly by the competent person scheme (or local authority Building Control) within a few weeks of notification. This confirms that the notifiable work was carried out in accordance with Part P.
• Minor Electrical Installation Works Certificate (MEIWC): Used only for smaller additions or alterations where no new circuits are created (such as adding extra sockets or light switches to an existing circuit).
• Consumer unit schedule: A clearly labelled chart or legend, typically affixed inside or beside the consumer unit, identifying which breaker controls each circuit, appliance, and area of the home.

The Electrical Installation Certificate should contain precise readings recorded during testing, including earth fault loop impedance, insulation resistance, and residual current device (RCD) trip times. These figures provide a technical baseline that future electricians will rely upon when carrying out routine testing or further modifications.

Tracking cable routes and hidden infrastructure

Standard wiring regulations dictate 'safe zones' for cables—such as running vertically or horizontally from switches and sockets. However, cable runs under floorboards, through joists, across lofts, or behind kitchen cabinetry are rarely standard or predictable once floor coverings and furniture are fitted.

Before walls are re-plastered or floorboards nailed down, take clear, well-lit photographs of all open chases, ceiling voids, and junction box locations. Include reference points like door frames or chimney breasts so the exact path of the cabling is unmistakable years later. These images help prevent accidental cable strikes when you or future owners drill into walls to hang heavy mirrors, shelves, or wall-mounted appliances.

Why these records matter when selling or maintaining your home

When selling a property in the UK, the Law Society's standard Property Information Form (TA6) asks detailed questions about electrical work carried out since 2005. Sellers must disclose rewires, consumer unit changes, and new circuits, and provide the accompanying Part P compliance certificates and Electrical Installation Certificates.

Missing certificates frequently lead to conveyancing delays, requests for expensive indemnity insurance policies, or requirements to pay for a last-minute Electrical Installation Condition Report (EICR). Storing your electrical certificates, test schedules, and in-progress photographs together on an independent platform like Project Passport ensures you have an organised record ready for tradespeople during future renovations or for solicitors during a property sale.

Electrical installations degrade over time due to wear, environmental factors, and changes in household demand. Keeping a clear service history of who worked on the system, when it was upgraded, and the baseline test values helps future electricians carry out periodic inspections efficiently and safely.