Full rewire vs partial rewire: what is the difference?

Glossary · Wiring, circuits and faults

How a rewire works

NICEIC describes rewiring as removing old, outdated or faulty cabling and installing modern replacements, either across the whole home or in certain locations.^{[1]NICEIC, Rewiring your house: an essential guide for homeowners} That is the whole difference between the two terms. A full rewire covers everything. A partial rewire covers part of the installation.

Rewiring is not a job for householders. NICEIC says it should only be carried out by a qualified, competent electrician and is not suitable for DIY.^{[1]NICEIC, Rewiring your house: an essential guide for homeowners}

Full rewire and partial rewire compared

The first column follows how our own full house rewire service is described: a full rewire replaces the entire installation and ends with testing and an electrical certificate.^{[5]Martin Day Electricians, Full House Rewiring in Leeds} NICEIC lists the same elements for a full job: removing old wiring, installing new wiring and replacing the fuse box or consumer unit.^{[1]NICEIC, Rewiring your house: an essential guide for homeowners} On the partial side, NICEIC refers to a partial rewire that focuses on the replacement of specific circuits.^{[1]NICEIC, Rewiring your house: an essential guide for homeowners}

How to decide

Age alone does not decide it. Electrical Safety First says it depends on the condition rather than the age: if the wiring has been tested and is in good condition and everything is working effectively, there is no requirement to rewire.^{[3]Electrical Safety First, Electrical Safety Advice for Earthing and Bonding} NICEIC says the way to find out is an Electrical Installation Condition Report, which will identify whether remedial work or a rewire is recommended.^{[2]NICEIC, Benefits of a rewire} Our guide to what an EICR tests explains what the inspector checks, and the observation codes show how serious each finding is.

NICEIC lists signs that a property may need rewiring: circuit breakers or RCDs tripping, blown fuses, flickering lights, discoloured sockets or switches, buzzing sounds, or a consumer unit without RCD protection.^{[2]NICEIC, Benefits of a rewire} If you notice burning smells or small electric shocks, contact an electrician immediately.^{[1]NICEIC, Rewiring your house: an essential guide for homeowners}

The rules that apply to both

In England and Wales, Part P of the Building Regulations applies to new work and to changes to existing installations, including rewiring.^{[4]Electrical Safety First, Part P of the building regulations - Explained} The work must either be notified to local authority building control or be done by a registered electrician on a government-approved scheme, who issues a Building Regulations compliance certificate and an Electrical Installation Certificate.^{[4]Electrical Safety First, Part P of the building regulations - Explained}

A partial rewire carries one extra point. Electrical Safety First says the safety of any new work depends on the earthing and bonding arrangements, so your electrician must check they are up to the required standard.^{[3]Electrical Safety First, Electrical Safety Advice for Earthing and Bonding}

Example

Wei lives in a 1970s semi in Moortown. After an EICR, the report shows the kitchen sockets and the upstairs lighting need attention, while the rest of the installation is in good condition. His electrician recommends a partial rewire of those circuits. Next door, Hannah has original wiring, a rewireable fuse box and round-pin sockets. Her EICR points to the whole installation, so she is quoted for a full rewire. Both homes get a certificate at the end.

What people get wrong

Many homeowners assume a partial rewire is a lesser version of the same job. It is a different decision. A partial rewire is right only where the inspection shows the remaining circuits are in good condition. Where the report points to wiring throughout the house, replacing a few circuits leaves the same risk elsewhere.

The second mistake is judging by age. Wiring that is decades old can pass, and newer wiring altered badly can fail. The EICR, not the date on the cable, is the evidence.

The bottom line

A full rewire replaces the whole installation. A partial rewire replaces the circuits or areas that need it and keeps the rest. An EICR from a registered electrician tells you which one your home needs. Both jobs fall under Part P and must be certified, and neither is a DIY task.