The consumer unit is the single most important piece of kit in the house. It is what stops a nail into a cable, a burst pipe over a light fitting, or a failing appliance from setting the fabric of the building on fire. In older Wingham cottages we still find rewireable BS 3036 fuses and plastic Wylex boards from the 1970s. Amdt 2 to BS 7671:2018 tightened surge protection requirements, so most new consumer unit swaps now include an SPD as standard.
What you get
- Metal-clad 17th/18th edition consumer unit sized to the property (typical village semi: 10-way; typical farmhouse with outbuildings: 16-way plus split load).
- Individual RCBOs on every circuit rather than a shared RCD. If one circuit trips, the rest of the house stays on. This matters more than most people realise the first time the freezer defrosts overnight.
- Surge protection device (SPD) fitted at the origin. Mandatory under Amdt 2 for most new installs, and worth having anyway if you have a rural overhead supply.
- Main earth conductor upgraded to 16mm if the existing is undersized. Main bonding to gas and water checked and upgraded to 10mm.
- Full circuit test on completion. EIC issued the same day, notified to Building Control under the Competent Person Scheme.
What it costs
Consumer unit / fusebox replacement: from £600. That covers a straight 10-way RCBO swap in a Wingham village semi with existing meter tails in good order. Farmhouse boards with sub-mains to outbuildings, old fabric-insulated tails at the meter, or missing main earths add cost. We quote fixed after a photo of the existing board and the meter position.
Common issues we find
- Wylex plastic boards from the 1980s with plug-in MCBs. Legal but ripe for replacement, particularly if the RCD is a single 63A upfront and you have both an EV charger and a shower on the same side.
- Missing or undersized main earth. Very common in cottages where the last upgrade was a fusebox change with no earth intervention.
- Sub-mains to a converted outbuilding running in 6mm T&E clipped along a fence. Legal-ish twenty years ago, not now. SWA and a properly earthed sub-board is the fix.
Amdt 2 note
BS 7671:2018 Amendment 2 (effective March 2022, mandatory September 2022) changed several requirements including surge protection and AFDD provision. Consumer unit work carried out to Amdt 1 up to that date is still compliant, but any new work now must meet Amdt 2. That is what we install.