Consumer Unit Upgrade Cost UK 2026 Fusebox Replacement Guide
Upgrading a consumer unit (fusebox) in the UK costs £450 to £800 including parts, labour, and Part P certification. It is notifiable work under Part P of the Building Regulations and must be done by a registered electrician (NICEIC, NAPIT, or equivalent). Common reasons for upgrading: old rewirable fuses, no RCD protection, adding new circuits (EV charger, kitchen remodel), or your unit is a recalled type.
Consumer Unit Upgrade Cost Breakdown
Consumer unit (new board): £80-150 for a quality 18th Edition metal consumer unit (Hager, Wylex, MK, Schneider). Labour: £300-500 for a registered electrician (4-8 hours work). Testing and certification: Included in most quotes — the electrician performs full testing and issues an Electrical Installation Certificate (EIC). Part P notification: Included when using a Competent Person scheme registered electrician. Total: £450-£800 depending on complexity, number of circuits, and location (London/SE is more expensive).
When You Need to Upgrade
Safety reasons: Old rewirable fuses (with wire fuse carriers) should be replaced with modern MCBs. No RCD protection — BS 7671 18th Edition requires RCD protection for all circuits. Recalled units (some Wylex and MEM units from specific periods). Adding circuits: Installing an EV charger, new kitchen, extension, or outbuilding. If there are no spare ways in your current consumer unit, you need an upgrade or a secondary board. Home sale/insurance: Some insurers and mortgage surveyors flag outdated consumer units. An upgrade makes your home easier to sell and insure.
What the Upgrade Involves
1. Initial assessment: Electrician inspects the existing installation, tests circuits, and identifies any issues. 2. Power off: Main supply is isolated. Work takes 4-8 hours — you will be without power during this time. 3. New board installation: Metal consumer unit with dual RCD or RCBO protection. 18th Edition compliant. 4. Circuit transfer: All existing circuits transferred to new board with appropriate MCBs/RCBOs. 5. Full testing: Insulation resistance, earth loop impedance, RCD trip times — all recorded on the EIC. 6. Certification: EIC issued and Part P notification submitted. Keep the certificate for future home sale.
Dual RCD vs RCBO Board
Dual RCD (split load): £80-120. Two RCDs each protecting half the circuits. If one RCD trips, half your circuits go off. Most common and cheapest option. Full RCBO board: £200-350. Every circuit has its own individual RCBO (combined MCB + RCD). If one circuit trips, only that circuit is affected — everything else stays on. More expensive but highly recommended, especially for homes with EV chargers, freezers, or home offices where you cannot afford to lose circuits unnecessarily.
| Item | Cost Range | Notes |
|---|---|---|
| Consumer unit (board) | £80-150 | 18th Edition metal, dual RCD or RCBO |
| Labour (4-8 hours) | £300-500 | Registered electrician |
| Testing & certification | Included | EIC + Part P notification |
| RCBO upgrade premium | £100-200 | Optional but recommended |
| Total (dual RCD) | £450-650 | Standard upgrade |
| Total (full RCBO) | £550-800 | Premium upgrade |
DIY — Absolutely Not
Consumer unit replacement is notifiable work under Part P. It is illegal to do it yourself unless you are a registered electrician. The work involves: working near the live incoming supply (dangerous), reconfiguring all household circuits, testing to BS 7671 standards, and issuing certification. Even if you are a competent DIYer, this is not a DIY job. The cost of a registered electrician (£450-800) is modest compared to the safety risk, legal liability, and insurance implications of unpermitted work. Always use NICEIC, NAPIT, or equivalent registered professionals.
Disclaimer: For educational reference only. Consult a licensed professional.