Single phase vs three phase supply
Most UK homes run on a single-phase electricity supply, which is enough for typical household use. Larger properties, workshops, or homes adding multiple EV chargers or heavy machinery sometimes need a three-phase supply instead — this is arranged with the network operator, not just your electrician, and can take weeks.
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.
LED lighting and energy-saving rewires
Swapping halogen downlights for LEDs is usually straightforward, but older dimmer switches often aren't compatible with LED drivers and need replacing alongside the bulbs, or you'll get flickering or a limited dimming range. If you're rewiring a room anyway, it's worth speccing LED-compatible circuits from the start rather than fixing dimmer compatibility later.
Wiring a loft conversion
A loft conversion typically needs new lighting and socket circuits, often a new consumer unit way if the existing one is already at capacity, and mains-wired interlinked smoke alarms are usually required by building control as part of the sign-off, not just recommended.
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.
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.
First fix and second fix, explained
On a rewire or new build, "first fix" is running cables through walls and floors before they're closed up; "second fix" is fitting sockets, switches and light fittings once decorating is done. Getting the timing right with other trades on site avoids cables being covered before they're tested.