Consumer Unit & Fuse Box Upgrade in Merton

About consumer unit & fuse box upgrade in Merton

A consumer unit upgrade replaces your existing fuse box or outdated consumer unit with a modern metal-enclosed unit that meets the 18th edition of the IET Wiring Regulations (BS 7671:2018+A2:2022). Modern consumer units use RCBOs or dual RCD protection to provide individual circuit protection, meaning a fault on one circuit does not trip the entire house. The metal enclosure is now mandatory under Amendment 3 to reduce fire risk. This is one of the most common electrical upgrades in UK homes and is often required before other work such as EV charger installation or adding new circuits.

If your home still has a rewirable fuse box with porcelain fuse holders, a plastic consumer unit, or an older board without RCD protection, it does not meet current safety standards. Without RCD protection, there is no automatic disconnection in the event of an earth fault — increasing the risk of electric shock and electrical fires. A consumer unit upgrade is also required if you need additional circuits (e.g., for an EV charger or electric shower) and your existing board has no spare ways. It is notifiable work under Part P and must be carried out by a registered electrician.

What's included

• Removal and disposal of old fuse box or consumer unit
• Supply and installation of new 18th edition metal consumer unit
• RCBOs or MCBs with dual RCD protection for all circuits
• New meter tails if existing ones are undersized or damaged
• Main earth and bonding conductor upgrades where required
• Supplementary bonding checks and upgrades
• Full testing of all circuits to BS 7671 standards
• Electrical Installation Certificate (EIC)
• Part P Building Control notification via competent person scheme
• Circuit chart and labelling of all ways

Typical cost

Consumer Unit & Fuse Box Upgrade in Merton typically costs £350–£800 per installation. Every job is different — describe what you need and a qualified electrician will quote you directly.

See full pricing breakdown →

Regulations & standards

• Part P of the Building Regulations (Approved Document P): Consumer unit replacement is notifiable electrical work. It must be carried out by an electrician registered with a competent person scheme (NICEIC, NAPIT, ELECSA) or inspected and certified by Building Control.
• BS 7671:2018+A2:2022 (IET Wiring Regulations, 18th Edition): The national standard for electrical installations in the UK. Specifies requirements for circuit protection, earthing, bonding, and the type and rating of protective devices in the consumer unit.
• Amendment 3 to BS 7671 — Metal Consumer Unit Enclosures: Since January 2016, all new or replacement consumer units in domestic premises must be enclosed in a non-combustible (metal) enclosure. This was introduced to reduce the risk of fire spreading from a consumer unit fault.
• Electricity Safety, Quality and Continuity Regulations 2002 (ESQCR): Governs the connection between the DNO supply and your installation. If the main fuse seal needs breaking during the upgrade, your electrician must arrange reinstatement with the DNO.