Metal Clad Consumer Units London — Amendment 3 Compliance

BS 7671 Amendment 3 was published on 1 January 2015 and applied to installation work designed from 1 July 2015 onwards. From that date, any new or replacement consumer unit installed inside a domestic dwelling has been required to use a non-combustible enclosure — in practice a steel ('metal-clad') unit.

Not retrospectively. A plastic board installed before July 2015 was compliant on the day it went in, and Amendment 3 did not require existing installations to be retrofitted. However, an EICR carried out today will normally code a plastic-bodied board within a dwelling as C2 (potentially dangerous) or C3 (improvement recommended) — and a C2 triggers the 28-day remediation requirement under the 2020 landlord regulations.

Yes, in certain contexts. Amendment 3 specifically targeted dwellings. Commercial premises, workshops, light-industrial units and outbuildings are not covered by Regulation 421.1.201 in the same way, and plastic enclosures meeting the relevant IP and impact ratings remain compliant in those locations. A4:2026 has not changed this position for non-domestic installations.

Three checks: the manufacturer label inside the door (most include a date code or production batch); the EIC or minor works certificate that should accompany the original installation; and a NICEIC inspection — distinctive design generations (Wylex Standard, Wylex NHXS, Hager VML, Schneider Acti9, MK Sentry plastic vs MK Sentry Metal) are recognisable on sight to an experienced inspector. We confirm age and compliance on the survey visit.

Intumescent compounds expand to many times their original volume on exposure to heat, sealing gaps and slowing the propagation of fire. Modern metal-clad consumer units use intumescent door seals and cable entry strips so that a fault inside the board is contained long enough to prevent ignition of surrounding fabric. Plastic boards have no equivalent containment mechanism — once the enclosure melts the fault escapes.

We do not install refurbished or reconditioned consumer units. The original BS EN 61439-3 type-test certification only applies to the unit as originally manufactured and supplied — a refurbished unit cannot carry the same conformance, and the manufacturer warranty is void. Every installation we carry out uses a new, current-production board from a major UK manufacturer.

EWS1 assesses external wall fire safety in residential blocks and does not directly address consumer units. However, where a block is undergoing EWS1 remediation, freeholders and managing agents commonly use the opportunity to bring shared and demised electrical equipment to current standards — including replacing pre-2015 plastic consumer units in individual flats. We work with managing agents on coordinated block-wide upgrades.

Yes — consumer unit replacement is notifiable work under Part P of the Building Regulations in England and Wales. As an NICEIC Approved Contractor we self-certify the installation and submit the Part P notification on your behalf. You receive the building regulations completion certificate from NICEIC within 4–6 weeks alongside the EIC issued on the day.

You can, until an EICR is required. Owner-occupiers are not legally compelled to replace a plastic board. But the moment you need an EICR — landlord registration, mortgage refinance, sale, insurance request — a pre-2015 plastic board will likely attract a C2 or C3 code requiring remediation. Replacing proactively at £750 is materially cheaper than rushed remediation against a deadline.

Most London selling agents now request a current EICR alongside the EPC at marketing. A pre-2015 plastic board flagged on the EICR is one of the most common reasons for a sale chain to stall or a renewal to be delayed. Upgrading to a metal-clad unit before going to market typically pays back in transaction speed and removes the most common pre-completion fault that solicitors flag.