Full rewire or part rewire? A full rewire replaces all the wiring in a property and suits old or deteriorated installations. A part rewire replaces only certain circuits or rooms and suits extensions, renovations or limited faults. Watsons Electrical Hugglescote Ltd assesses your existing wiring first, then recommends the most suitable option.
At a glance
- Full rewire
- Replaces the wiring throughout the property
- Part rewire
- Replaces only the circuits or rooms that need it
- Deciding factors
- Test results, the condition of the cables and your plans for the property
- First step
- Have the existing installation inspected and tested
- Building Regulations
- Notifiable in England when new circuits are added
What is a full rewire?
A full rewire replaces the electrical wiring throughout a property. It normally includes new cables, sockets, switches and light fittings, and usually a new consumer unit. It is the usual choice for older homes where the cables are deteriorated, damaged or no longer suited to modern electrical demands.
What is a part rewire?
A part rewire replaces the wiring in certain areas or circuits only. It suits a home where testing shows problems in some circuits, or where you are extending, renovating or updating one part of the property. It avoids replacing wiring that does not need changing.
How do a full rewire and a part rewire compare?
The table compares the two options on the points homeowners ask about most.
| Full rewire | Part rewire | |
|---|---|---|
| Scope | All wiring in the property | Selected circuits or rooms |
| Typical reasons | Old, brittle or damaged cables throughout | Faults in some circuits, an extension or a renovation |
| Consumer unit | Usually replaced | Replaced if it is out of date or cannot take the new circuits |
| Typical duration | Around one to two weeks for an average house | A few days |
| Disruption | Higher: floors lifted, walls and ceilings opened, power off in stages | Lower: limited to the areas being rewired |
| Cost | Higher, because more cable and making good is involved | Lower, because less is replaced |
How do I decide between a full rewire and a part rewire?
The decision comes from the condition of your wiring and your plans for the property. Work through these steps:
- Get the installation tested. An Electrical Installation Condition Report shows which circuits are sound and which are not.
- Read the codes. Widespread C1 or C2 observations point to a full rewire, while a few isolated ones may need only a part rewire.
- Think about your plans. If you are planning an extension, new kitchen or full renovation, rewiring first saves opening up finished walls later.
- Ask for the scope in your quotation. Check exactly which circuits and rooms are included.
- Plan for disruption. Ask how long power will be off and whether you can stay in the property.
Do both need Building Regulations notification?
A full rewire and any part rewire that adds a new circuit are notifiable under Part P of the Building Regulations in England. The work must be carried out by an electrician registered with a competent person scheme or be notified to Building Control. See our guide to Part P and electrical building regulations.
Frequently asked questions
Is a part rewire cheaper than a full rewire?
Usually, yes, because less cable is replaced and less making good is needed. A part rewire is only suitable if the rest of the installation is in satisfactory condition.
Can a part rewire turn into a full rewire?
Yes. If testing or opening up the property shows worse wiring than expected, the scope may need to change. Agree how any change will be handled before work starts.
How do I know which circuits need replacing?
Testing shows which circuits fail and why. An electrician records the results in a report and can mark the circuits that need replacing.
Will a rewire damage my decoration?
A full rewire usually means lifting floorboards and cutting channels in walls, so some making good is needed. Plan to redecorate afterwards and ask what making good your quotation includes.
Should I rewire before or after renovating?
Before. Cables are easier to run while walls, ceilings and floors are open, which avoids damaging new plaster and decoration.
Sources and further reading
Last reviewed: by Watsons Electrical Hugglescote Ltd. Questions about your own property? Call 07359 854049.