Consumer Unit (Fuse Box) Upgrade Cost Guide, Chiswick (2026)

Signs your consumer unit needs upgrading

The clearest sign is a genuinely old-style fuse box with rewireable fuse wire rather than circuit breakers. If you've ever had to replace a piece of fuse wire yourself, that's your answer. A plastic (non-metal) consumer unit installed before the 2016 regulation change is another common issue in Chiswick's older housing stock, since current regulations require a metal or fire-resistant enclosure.

Other warning signs include a board with no RCD protection at all, frequent nuisance tripping, or an EICR that's come back with C1 or C2 codes. If your mortgage lender or insurer has specifically asked for evidence of a safe, compliant board, that's usually the point people call us.

What a consumer unit upgrade involves

We start by isolating the supply, which occasionally needs coordinating with your meter operator depending on the setup. The old board is removed and replaced with a metal or fire-rated enclosure, in line with Amendment 2 of BS7671. Depending on budget and how the property's circuits are laid out, we'll specify either a split-load dual RCD board or a full RCBO board where every circuit has its own individual protection, which avoids a fault on one circuit tripping the whole house.

Every circuit is tested and labelled, including insulation resistance, earth loop impedance, and RCD trip times. Once everything checks out, we issue an Electrical Installation Certificate and notify the work under Part P through NAPIT's self-certification scheme, so there's no separate council building control application or fee.

Typical consumer unit upgrade costs in Chiswick in 2026

For a standard domestic property on a single-phase supply, a straightforward dual RCD board with 8 to 10 ways typically costs £450 to £650 fully fitted and certified. A full RCBO board, where each circuit has its own dedicated protection, generally runs £650 to £950 depending on the number of circuits.

Period properties in Bedford Park and Grove Park often need a bit more than just the board swap. Testing regularly turns up issues that need addressing at the same time, such as earth bonding to gas and water that doesn't meet current standards, or sections of old rubber or lead-sheathed cable still in use beyond the board. Where remedial work like this is needed, it typically adds £150 to £400 per circuit on top of the board upgrade itself.

Do you need a bigger job than just the board?

This is the question worth asking before you commit to a quote. A lot of Chiswick's period housing stock still has some of its original wiring downstream of the consumer unit, and a board upgrade on its own won't fix that. If it's been a while since the property was last inspected, it's often more cost-effective to start with a full EICR. That gives you a clear picture of what actually needs doing, rather than paying for a new board only to find bigger issues a few months later.