Consumer unit replacement cost: what a fuse box swap should cost

Consumer unit replacement cost in 2026 runs about £450 to £750 outside London and £700 to £1,200 in London, with a national average around £485 to £600 for a typical 10-way board. Harlow prices to the South East band. But the price is the easy part of this page — the decision that actually matters is what kind of board you get for it, and almost nobody will raise it with you.

What it costs in 2026

Published UK figures, checked September 2026. These include the unit, labour, testing, certification and Part P notification — the whole job, not the box.

For scale: a dual-RCD board from a mainstream manufacturer costs roughly £80–£160 at trade price. So on a £550 job you are buying about £100 of hardware and £450 of labour, testing and certification. That ratio is worth holding in mind, because it explains why a cheap quote is almost never a cheaper box — it is less time, less testing, or no certificate.

The decision nobody explains: dual RCD or all RCBO

This is the part the cost guides skip, and it is the only genuinely important choice you make.

What you probably have now

Harlow's housing stock skews heavily to post-war new-town building, much of it part-rewired once already, so mixed-age installations are the norm here rather than the exception. Four generations of board turn up:

The steel enclosure is a requirement, not a style choice: the point is that a fire starting inside the board — usually at a loose connection — should not escape into the building fabric. A plastic board is not illegal, because it complied when it went in, but it dates the installation.

What the current standard adds

The current published version of the wiring regulations is BS 7671:2018+A4:2026. Two things in it change what a new board should contain, and both are worth asking about rather than discovering on the invoice:

• Arc fault detection (AFDD). Regulation 421.1.7 makes AFDDs mandatory on single-phase final circuits supplying socket-outlets up to 32 A in higher-risk residential buildings, houses in multiple occupation, purpose-built student accommodation and care homes. In an ordinary house they are recommended, not required. They add real cost, so the question is which category your property is in — and if you let the property as an HMO, this is a requirement and not a suggestion.
• Surge protection (SPD). Whether a domestic board needs surge protection is now a question the designer has to answer rather than an optional extra on a price list. Ask whether one is included, and if not, on what basis it was left out.

It is notifiable, and that has consequences

Replacing a consumer unit is notifiable work under Part P of the Building Regulations in England and Wales. A registered electrician self-certifies and notifies Building Control on your behalf; an unregistered one means you notify Building Control yourself, before the work starts, and pay their fee. The consequence is deferred rather than absent — a missing certificate for a board change is a standard conveyancing enquiry, and "a friend did it" costs more to resolve at sale than doing it properly now. See Part P: what is notifiable, and verify registration on the Registered Competent Person Electrical register before you book.

What you should get at the end

• An Electrical Installation Certificate — not a Minor Works Certificate, because a board change is not minor works.
• A schedule of test results, circuit by circuit. This is the part people forget to ask for and the part that proves the work.
• A Building Regulations compliance certificate from the scheme provider, usually within a few weeks.
• A legible circuit schedule inside the board, so the next person knows what is what.
• Your old board photographed before removal, if you want a record of what was there.

When a new board is the wrong purchase

Two cases, and both cost people money:

• You are replacing it because something keeps tripping. A new board will not fix a fault on a circuit — a more sensitive board detects it more reliably. Diagnose first: electrical fault finding, and why an RCD keeps tripping.
• You do not yet know the condition of the circuits. If the installation is old enough that a board change is on the table, an EICR first tells you whether the board is genuinely the priority, or whether you are about to put a new board on wiring that needs rewiring.

If you let the property, the board change and the statutory inspection interact — see the landlord certificate rules. And if you are adding a circuit rather than replacing the board, whether there is a spare way with capacity is the whole question: garage and outdoor electrics.

Before you get quotes

1. Photograph the inside of the existing board and the meter tails.
2. Count the circuits — it sets the board size and the testing time.
3. Ask for all-RCBO explicitly, and get the price difference in writing.
4. Ask what the price assumes about earthing, bonding and the condition of the circuits.
5. Confirm the certificate and the Part P notification are included, not extra.
6. Ask whether an SPD is included, and if not, why not.

Quotes priced per job rather than per hour are the norm here, and for good reason — see electrician hourly rates for why comparing rates tells you almost nothing about comparing quotes.