Consumer Unit Upgrade: What Electricians Actually Fit in 2026

Quick answer

For most UK homes in 2026 the standard fit is a metal consumer unit populated entirely with Type A RCBOs, a Type 2 surge protection device (SPD), and bidirectional devices wherever solar, battery storage or an exporting EV charger is involved or planned. AFDDs are mandatory only in specific higher-risk building types and are a recommendation everywhere else. A dual-RCD split-load board is still compliant and still the budget option, but it is 2016's answer, not 2026's.

Why boards actually get changed

Nobody wakes up wanting a new consumer unit. In practice the triggers are one of four things: an EICR has coded the existing board (rental compliance, a house sale, insurance), solar or an EV charger is going in and there are no spare ways, a rewire or extension, or the board is genuinely past it - rewireable fuses, no RCD protection, scorch marks around the terminals.

Worth being straight about the first one, because it is where most of the mis-selling happens. BS 7671 is not retrospective. An old plastic consumer unit in good condition, with working RCD protection, is not "illegal" and is not automatically dangerous. On an EICR it will typically attract a C3 (improvement recommended) rather than a C2, unless it sits under a timber staircase or on the sole escape route, or shows signs of thermal damage. If a report has coded your board and you want to understand what the codes actually mean before spending money, read our guide to EICR codes explained.

That said, once you are paying for a board change for any reason, it makes no sense to fit yesterday's spec. Here is what the current spec looks like and why.

Metal enclosures: the Amendment 3 everyone half-remembers

Since January 2016, consumer units in domestic premises have had to have an enclosure made of non-combustible material, which in practice means ferrous metal. That came in with Amendment 3 to the 17th Edition (Regulation 421.1.201) after fire investigation work, notably by London Fire Brigade, linked a run of house fires to overheating connections inside plastic consumer units.

Two things worth knowing. First, the metal case does not stop a fire starting - a loose neutral will cook happily in any enclosure - it contains the fire long enough to matter. Which is why the quality of the terminations inside is still the main event. Second, there are now two "Amendment 3s" in circulation: the 2015 one that gave us metal boards, and Amendment 3:2024 to the 18th Edition, which is about bidirectional devices (more below). When someone on site says "Amendment 3", ask which one.

Every board worth fitting today is metal and built to BS EN 61439-3, so this one takes care of itself. It only matters if someone tries to sell you a new plastic board from old stock. Walk away.

RCBOs vs dual RCD split load: the real decision

A dual-RCD board splits your circuits into two groups, each protected by one 30mA RCD. A full RCBO board gives every circuit its own combined MCB and RCD.

The dual-RCD board exists because it was the cheap way to meet the 17th Edition's RCD requirements. Its weakness is obvious the first time something goes wrong: one earth fault takes out half the house, including the freezer and the fridge, and finding which circuit caused it means splitting the board down - often at a call-out rate, often in the dark. There is also a quieter problem: modern homes are full of electronics with a small standing earth leakage (LED drivers, inverter-driven appliances, IT kit). Stack six circuits behind one 30mA RCD and the accumulated leakage can sit close enough to the trip threshold that the RCD becomes twitchy for no findable reason. Design guidance is to keep standing leakage well under a third of the RCD rating, and on a shared RCD that budget disappears fast.

RCBOs fix all of it. One fault loses one circuit, which is also the spirit of Regulation 314 - divide the installation to minimise inconvenience. Fault-finding takes minutes instead of an evening. Single-module RCBOs mean the board is no bigger than a dual-RCD equivalent, and device prices have fallen far enough that the gap between the two options is now modest money on a job dominated by labour.

Verdict: full RCBO is what good electricians fit by default in 2026. Dual RCD is defensible on a very tight budget, a small flat with five or six ways, or a landlord doing a fleet of them - it is compliant, just not what I would put in my own house.

One more thing while we are on devices: Type A RCDs/RCBOs are the practical minimum now. Type AC devices can be blinded by the DC components that modern loads produce, and the 18th Edition's selection rules leave almost no honest justification for fitting them in a home full of LED drivers, an induction hob and a heat pump.

SPDs: stop debating, just fit it

Amendment 2:2022 rewrote Section 443, and the short version is that a surge protection device at the origin is now the default position for new consumer unit installations. The old risk-assessment escape route is gone; the only realistic opt-out left is a single dwelling where the owner formally decides the protection is not justified - and any electrician using that route should get the decision in writing.

Honestly, declining is daft. A Type 2 SPD is a modest line on the quote, and it is standing in front of your solar inverter, heat pump controls, smart meter comms, TV, and every laptop in the house. Many boards now come with the SPD factory-fitted, which is the tidiest way to do it. Type 1 devices only come into play if the building has structural lightning protection, and Type 3 point-of-use protection is an optional extra for sensitive kit, not a requirement.

So: an SPD on a new board is not an upsell. If your quote does not include one, ask why.

AFDDs: required vs recommended, honestly

Arc fault detection devices (AFDDs, to BS EN 62606) monitor for the signature of arcing - the classic case being a damaged flex or a loose connection quietly cooking behind furniture. Amendment 2:2022 (Regulation 421.1.7) made them mandatory on socket-outlet circuits rated up to 32A in four settings: higher-risk residential buildings over 18 metres, houses in multiple occupation, purpose-built student accommodation, and care homes.

Everywhere else - which is nearly every ordinary home in Britain - they are recommended, not required. And they are expensive: an AFDD costs several times what an RCBO does, so populating a whole board with them can roughly double the material cost of the job.

My honest take for a standard owner-occupied three-bed: the technology is genuinely useful, and if budget is no object, fine. A sensible middle path is one or two AFDDs on the highest-risk socket circuits - a loft conversion with beds, a garage full of extension leads - and RCBOs elsewhere. But if a quote for a normal house presents AFDDs as mandatory, that is either a misreading of the regs or an upsell. Neither should fill you with confidence about the rest of the job.

Bidirectional devices: the new Amendment 3 (2024)

Amendment 3:2024 added Regulation 530.3.201, and it exists because the way we use electricity changed direction. Solar PV, battery storage and vehicle-to-grid EV chargers push current back through the board, and some protective devices are only designed and tested for current flowing one way - they have designated line and load terminals.

The rule is simple: where current can flow both ways through a device, the device must be suitable for it, which means bidirectional per the manufacturer's declaration - not per the wholesaler's guess. Several manufacturers now declare their whole device range bidirectional; others are device-by-device. If there is any chance of solar, a battery or an exporting charger in the life of this board - and in 2026, there is - make bidirectional devices a line in the spec, not an afterthought. If an EV charger is part of the plan, our guide to EV charger installation and testing covers the supply-side questions that go with it.

Boards electricians actually fit

Brand wars on the forums are mostly noise - every board here is metal, built to BS EN 61439-3, and will do the job. But there are real differences in device cost, range depth and support.

Board	Best for	The honest word
FuseBox F2	The value default	Cheap, compact RCBOs, SPD versions off the shelf, bidirectional devices - the range you see in half the vans in the country for a reason
Hager Design 10	Quality-first jobs	Costs more, and you feel why in the busbar, terminals and device range (including AFDDs); proper technical support behind it
Wylex NM range	Availability and familiarity	Heritage brand, solid boards, on the shelf at every wholesaler when you need a device on a Friday afternoon
BG Fortress	Tight budgets and landlord fleets	Basic but compliant; sensible choice for a dual-RCD swap where cost rules

If I am speccing with someone else's money, it is Hager. With my own, on a straightforward domestic board, the FuseBox F2 is hard to argue against. What matters far more than the badge is who installs it.

What a good installation looks like

A board change is really a testing job with some fitting in the middle, and this is where the cheap quote falls apart.

Before the old board comes off the wall, a good electrician tests the existing circuits - insulation resistance in particular - because a new board will expose faults the old rewireable fuses tolerated for decades. Borrowed neutrals between lighting circuits are the classic: invisible for forty years, then the new RCBOs trip on day one. A professional quote will say plainly that pre-existing circuit faults are chargeable extra, because they are unknowable in advance.

The visible tells of a good job: meter tails upgraded where needed (typically 25mm² on a 100A supply), the earthing conductor and main protective bonding to gas and water brought up to standard (typically 16mm² and 10mm²) - a board change is exactly the moment this must be checked, which is why "extra for bonding" on a quote is usually legitimate. Inside the board: conductors dressed, terminals torqued to the manufacturer's settings, a completed circuit chart on the door, and safe isolation arranged properly rather than an unauthorised pull of the cut-out fuse.

Then the paperwork. A consumer unit change requires full initial verification - continuity, insulation resistance, polarity, earth fault loop impedance, RCD tests - recorded on an Electrical Installation Certificate, not a minor works certificate, with the results run through a proper multifunction tester like the Megger MFT1741+. If you want to understand the loop impedance numbers on your certificate, see maximum Zs values explained, and for what the test kit itself should look like, our best multifunction tester guide. In England and Wales the work is notifiable under Part P, normally via the electrician's competent person scheme - the notification and certificate are part of what you are paying for. No cert, no deal.

What drives the price (and what doesn't)

I will not invent figures, but the factors are consistent. A straightforward like-for-like swap is roughly a day's work for one electrician; the spread on quotes comes from:

• Number of circuits - more ways, more devices, more testing time
• Device choice - dual RCD is cheapest, full RCBO is the modest step up, AFDDs multiply device cost several-fold
• SPD - small money, often already in the board
• What gets found - bonding upgrades, tail upgrades, insulation faults, borrowed neutrals; on older installations the remedials can outgrow the board itself
• Isolation - if there is no isolator switch, arranging supply isolation adds a step
• Region and access - city rates, awkward cupboards, making good

Be suspicious of a quote dramatically below the others. The board is a few hours of fitting; the value is in the testing, the remedials done properly, and the certificate. That is exactly where the cheap job cuts.

Required vs upsell: the summary

Item	On a new board in a normal house	Status
Metal enclosure	Yes	Required (421.1.201)
30mA RCD protection on virtually all circuits	Yes	Required
Type A devices (minimum)	Yes	Required in practice
Type 2 SPD	Yes, barring a formal owner opt-out	Default requirement
Bidirectional devices	Where solar/battery/V2G can back-feed	Required in that case
Full RCBO over dual RCD	Strongly advised	Good practice, not mandatory
AFDDs throughout	No	Recommended only - mandatory only in HRRBs, HMOs, student accommodation, care homes

FAQ

Is my plastic consumer unit illegal?

No. The metal enclosure rule applies to new installations, not retrospectively. A plastic board in good condition with working RCD protection typically gets a C3 on an EICR - a recommendation, not a fail - unless it is on an escape route, under a timber staircase, or showing thermal damage.

Do I have to fit AFDDs?

Only if the property is a higher-risk residential building over 18m, an HMO, purpose-built student accommodation or a care home - and then only on socket circuits up to 32A. For an ordinary house they are recommended, and anyone telling you otherwise is selling.

Can I replace a consumer unit myself?

In England and Wales it is notifiable work under Part P. A registered electrician self-certifies through their scheme; a DIYer must notify building control before starting and pay for the privilege, and still needs the test instruments and competence to complete an Electrical Installation Certificate. Realistically: no. This is the one job in the house where the paperwork and testing genuinely are the product.

How long does a consumer unit change take?

A clean swap on a healthy installation is a day for one electrician, including testing. Older properties routinely run longer once insulation faults or borrowed neutrals surface - which is why good quotes carve out pre-existing faults as chargeable extras.

Why has my electrician quoted extra for earth bonding?

Because before energising a new board they must confirm the earthing and bonding are up to standard, and on older houses the bonding to gas and water is often undersized or missing. It is not an upsell - it is the part of the job that makes everything else safe.