Fuse Box / Consumer Unit Replacement Whetstone

Cheaper together. A Whetstone N20 kitchen extension around Whetstone High Road or off Totteridge Lane adds 3-4 new circuits — cooker, induction hob, dishwasher, washing machine. Barnet Council Building Control notification under Part P. Pre-2010 N20 boards are typically dual-RCD or at-limit on spare ways. Single mobilisation saves about £500.

Usually yes for the supply. Whetstone N20 semis and detached properties typically have 80A supplies — fine for a basic garage-office, marginal once a wall heater or AC unit is added. Bigger Whetstone detached homes off Totteridge Lane sometimes have 100A supplies already. We check the cutout, diversity-calc, and apply for an uplift via UK Power Networks if needed.

Yes — typically a topology issue. Whetstone properties commonly have a 1990s-2010s dual-RCD board. Family-of-five kitchen on one RCD bank crosses 30 mA cumulative leakage. Full-RCBO fixes permanently.

Both protect against electric shock and electrical fire. The difference is granularity.

• RCD consumer unit (typically dual-RCD): Two big trip switches, each protecting a group of circuits. If one circuit faults, the whole RCD group trips — you lose the kitchen, lights, and sockets together.
• RCBO consumer unit (one RCBO per circuit): Each circuit has its own combined trip switch. If the kitchen socket faults, only that circuit goes off — the rest stay live.

Why we recommend RCBO for most Whetstone installs:

• Faster fault diagnosis — you know immediately which circuit is faulty
• Less disruption — one bad iron doesn't kill the whole upstairs lighting
• Better with modern electronics — RCBOs are more sensitive and reliable

When dual-RCD is fine: small flats with simple circuit layouts, properties on a tight budget, short-term landlord-let where cost beats convenience.

Cost difference: typically £150 between dual-RCD (£800) and full RCBO (£950). For most homeowners we recommend the RCBO upgrade — it pays for itself the first time a fault localises rather than killing half the house.

This is the most common scare we see in Whetstone — the fear-driven upsell to landlords.

Honest answer: plastic fuse boxes fitted before 1 January 2016 are still legal and don't automatically fail an EICR. They were the standard at the time of fitting. They become a problem only when:

• The plastic enclosure shows signs of overheating or burn marks (genuine C2)
• The board has no RCD protection on socket circuits (the fail reason isn't the plastic — it's the missing RCDs)
• The original installation was non-compliant when fitted

Since 1 January 2016, all new consumer units in domestic properties must be made of non-combustible material (typically metal). This is a forward-looking requirement — your existing plastic fuseboard doesn't get retrofitted just because the rules changed for new installs.

What you should worry about: not the colour of the box. Worry about RCD coverage, the age of the wiring, whether the existing fuse box has been properly maintained, and whether your EICR has C1/C2 codes against the consumer unit specifically. If an electrician quotes you for "a metal consumer unit because plastic fails EICR" without that nuance — get a second opinion.

Supply — most Whetstone N20 properties on 80A, larger detached on 100A. CU — needs a spare 32A way or it's part of the install. RCBO — Type B for cheaper chargers, Type A for higher-spec. Diversity calc with EV installer beforehand.

Almost always yes. The new consumer unit is the brain; your existing circuits are the nervous system. We connect to your existing circuit cables — they don't get rewired.

What we test before we commit:

• Insulation resistance on every circuit (must be at or above 1MΩ; healthy 1990s+ installs typically read above 200MΩ)
• Earth continuity — needed for RCD/RCBO to work safely
• Loop impedance — the circuit's ability to clear a fault

If a circuit fails any of these tests, we tell you before we commit. Options:

• Single circuit fix (£100-£300) — repair the fault and continue
• Targeted partial rewire of just that circuit (£300-£600)
• Hold the upgrade and discuss whether a partial or full rewire is now better value

Common Whetstone scenarios where wiring fails: 1950s-60s rubber-insulated cable in upstairs lighting circuits (Oakleigh Road North and Oakleigh Road North period properties), borrowed neutrals from DIY work, undersized cables on extension circuits.

We never "just power it back up" with a circuit that failed testing — that's how fires start. Honest tradeoffs only.

Honest answer: the £800 is fixed for the standard scope. Any extras are quoted upfront, never sprung on you mid-install.

What's covered in £800 (no surprise add-ons):

• The new consumer unit / fuse board (quality metal, 6-10 ways)
• RCD protection on socket and lighting circuits
• Re-terminating every existing circuit, properly labelled
• Full insulation, earth, and RCD testing on every circuit
• The Electrical Installation Certificate (EIC)
• Plaster patching with bonding plaster around the install

What CAN add to the price (we tell you before we start, with a fixed quote):

• Circuits failing insulation testing — we'll show you the readings, and you decide: targeted repair (£100-£300 per circuit) or hold the upgrade for a partial rewire conversation
• Incoming supply needs upgrading — rare; happens when adding heavy load like an EV charger or heat pump. We tell you upfront if your supply is borderline
• You opt for the premium tier — £950 (RCBO every circuit + surge protection) or £1,200+ (larger split-load board)

What we never do: discover a "problem" mid-install and charge you for it without your sign-off first. If we find something during testing, work pauses until you've decided. No scope creep.

Yes — surveyors flag pre-2010 boards. Whetstone N20 buyers' solicitors typically ask for a recent EICR; C2 codes on an aged board become a negotiation point. Upgrading before listing nets £2-3k after the £800 spend.

Now is usually smarter. ASHPs need 25-32A dedicated circuit, Type 2 SPD, CU sized for load. Pre-2010 Whetstone board means heat-pump installer quotes the upgrade as an add-on at a markup. Doing CU first means heat-pump quote is just the heat pump.

Yes — and we set up Whetstone consumer units for it as standard. What we include:

• Spare 32A way on the fuseboard, labelled and ready for a 7kW or 22kW EV charger install
• Adequate supply headroom — we check your incoming supply and tell you upfront if a heat pump or EV charger needs a supply upgrade (often the headroom is fine, but worth confirming)
• SPD (surge protection) on the premium tier (£950) — protects every modern electronic in the house from voltage spikes
• Smart-home-ready circuits — neutrals to switch positions if you specify (most period houses don't have these, blocking smart switch installs later)

What gets retrofitted later costs more. Adding an EV charger circuit to an existing fuse box: £400-£600 extra labour because we need to chase walls, lift floor coverings, and isolate the supply again. Specifying it during the consumer unit upgrade: marginal cost only.

Tell us at the survey stage what you might add in the next 5 years — EV, heat pump, hot tub, garden room, second EV charger, home office. We size the board around your plans, not just your current circuits.

Almost never. Unlike a rewire, a consumer unit replacement is contained to the meter cupboard — usually under the stairs, in a hallway recess, or in a kitchen cupboard. The work stays in that one spot.

What we do during the install:

• Disconnect existing circuits at the old fuse box, label every cable
• Remove the old fuseboard from its mounting point
• Mount the new consumer unit in the same position (same screw holes where possible)
• Re-terminate every circuit into the new board
• Test, certify, and label every circuit on the new unit's chart

What we don't do:

• Chase walls
• Lift floorboards (unless an existing cable is too short to reach the new connection point — rare)
• Disturb skirting, sockets, or switches anywhere else in the house
• Affect any decoration outside the meter cupboard

The only plaster work: if the new board is a different physical size than the old one, we may need to patch a small area of bonding plaster around the mounting position. That's included; finishing coats and any decoration are a decorator's job.

Whetstone properties with the original fuse box in a tight under-stairs space sometimes need a little extra work to fit a wider modern board — we'll show you the position before we start so you can decide whether to keep it where it is or relocate.