When does a consumer unit need replacing?
Older fuse boxes with rewireable fuses or plastic (rather than metal) casings don't meet current wiring regulations and are a common reason a rewire quote comes in higher than expected. A modern consumer unit uses RCBOs, which cut power to a single faulty circuit rather than the whole property.
New build and extension electrical work
Wiring an extension or new build from scratch is different from rewiring an existing room — it's planned around final wall positions and fittings before plastering, so timing with your builder matters. First-fix electrical work (cabling inside walls) has to happen before plastering; second-fix (sockets, switches, fittings) after.
What affects the cost
Cost depends on the scope of the job, how much of the property needs to be accessed, the age and condition of the existing wiring, and whether the consumer unit needs upgrading. A single socket replacement is quick and low-cost; a full rewire in an older property takes longer, partly because of the making-good work afterwards.
DIY electrical work vs when you need a professional
Under Part P of the Building Regulations, certain electrical work in a home is notifiable — it has to be carried out by a registered electrician who can self-certify it, or separately inspected by your council's building control. New circuits, consumer unit replacements, and any new work in a kitchen or bathroom are notifiable. Like-for-like socket or switch swaps usually aren't.
Three steps to hiring the right electrician
First, confirm they're registered with NICEIC or NAPIT and ask to see their registration number. Second, get a written quote that itemises labour and materials separately, not just a total. Third, ask what certificate you'll receive when the work's done — for notifiable work, you're entitled to a Building Regulations compliance certificate.
Powering a garden office or outbuilding
Running power to a garden office or outbuilding usually means an armoured cable buried below the recommended depth, its own small consumer unit, and RCD protection at the supply end. This is notifiable work and typically needs building control sign-off alongside the electrical certification.
How often should wiring be tested?
The IET recommends an electrical inspection every 10 years for an owner-occupied home, 5 years for a rented property, and on change of occupancy for some property types. A periodic inspection is different from routine maintenance — it's a formal check against current wiring regulations, not just a visual look.
Electrical emergencies — what to do
If you smell burning, see sparks, or a breaker keeps tripping and won't reset, turn off the affected circuit and call an electrician. Don't reset a tripped breaker more than once if it trips again immediately — that usually means a fault, not a one-off.