House Wiring Cost in the UK (2025)
First-fix wiring for a new extension or build costs £800–£3,000+. Adding extra circuits to an existing property costs £200–£800 per circuit.
First fix vs second fix wiring
First fix electrics involves running cables through walls, floors, and ceilings before plastering — typically done when building an extension or undertaking a major renovation. Second fix is the finishing stage: fitting sockets, switches, light fittings, and connecting everything up. Both stages are required for a complete installation.
Adding circuits to an existing home
If you need extra sockets, a dedicated circuit for an EV charger, or wiring for a garden office or outbuilding, an electrician can run a new circuit from your consumer unit. This is much cheaper than a full rewire and can be done room by room as needed.
Cost Breakdown
All prices are indicative UK averages for 2025. Actual costs vary by location, specification, and contractor. London and South East rates are typically 20–35% higher.
| Item | Low | High |
|---|---|---|
| First fix electrics (single room) | £400 | £900 |
| First fix (single-storey extension) | £800 | £2,500 |
| Full house wiring (3-bed) | £4,500 | £8,000 |
| New circuit from consumer unit | £200 | £600 |
| EV charger circuit | £400 | £900 |
| Garden office wiring | £600 | £1,500 |
What Affects the Cost?
- ✓Whether this is first fix during a build or adding to existing wiring
- ✓Number of sockets, circuits, and light fittings required
- ✓Distance from consumer unit to the work area
- ✓Whether the consumer unit needs upgrading
- ✓Location — London and South East rates are higher
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Post a Job — It's FreeFrequently Asked Questions
Does wiring work need to be notified to Building Control?
Yes — any notifiable electrical work must be carried out by a Part P registered electrician who can self-certify, or notified to your local Building Control authority. Minor works like adding a socket do not require notification.
How do I know if my consumer unit needs upgrading?
Old-style fuse boards with rewirable fuses should be replaced with a modern consumer unit with RCDs. An electrician can assess this during a first visit. Replacement typically costs £400–£700.