The void window is the only time a consumer-unit (CU) upgrade doesn’t disrupt a tenant — and the only time the cost makes sense at scale. For housing association asset managers, the CU upgrade decision is now a void-turnaround conversation, not a capital-planning one. Here’s the specification that keeps the work compliant, the schedule predictable and the cost defensible.
Why old CUs are the most common Awaab’s Law remedial
An old wooden-back or first-generation plastic CU is the most-flagged issue on stock-condition EICRs. The combination of:
- No RCD protection, or partial protection on a single rail.
- Combustible enclosure material (pre-Amendment 3 of the 17th Edition).
- Re-wireable fuses or older MCBs without the response curves required for modern circuits.
- No dedicated protection on circuits running through bathrooms or kitchens.
…turns into a C2 finding on a current EICR. C2s have a 28-day target clearance, and clearing 28 of them across stock at month-end is the scheduling problem that defeats most reactive contractors.
18th Edition / Amendment 2 requirements
The current requirement for a domestic consumer unit (BS 7671:2018 + Amendment 2:2022):
- Non-combustible enclosure (metal, typically steel).
- RCD protection on every circuit — either via main switch RCD, dual-RCD configuration, or RCBOs.
- Surge protection device (SPD) on the supply side, unless a documented risk assessment supports omission.
- Arc Fault Detection Devices (AFDDs) recommended for circuits in care homes, HMOs and high-risk locations.
For HA stock, the practical implication is that a 2026 CU upgrade should be RCBO-per-circuit with SPD, in a steel enclosure, regardless of whether the property is single-let or HMO.
Specifying RCBO vs split-load
Two configurations dominate the upgrade conversation:
- Split-load (dual-RCD): Two RCDs feed two banks of MCBs. Cheaper, faster to install. Drawback: a trip on one RCD kills half the property’s circuits.
- RCBO-per-circuit: Each circuit has its own combined RCD + MCB. Higher unit cost. Drawback: install time. Benefit: a fault on one circuit doesn’t take out other circuits.
For tenanted stock, RCBO-per-circuit is the working standard — a single tenant call-out at 2am because the freezer tripped the kitchen RCD and took the upstairs lights with it is the kind of incident that produces a complaint, not just a fault.
Scheduling the upgrade inside a void turnaround
A void window is typically 2–4 weeks. The CU upgrade needs to land inside that, alongside cleaning, redecoration and any other pre-letting work. The sequence that works:
- Day 1–2 of void: EICR booked and completed. C1/C2 findings flagged.
- Day 3–4: CU upgrade scheduled, ideally the same engineer or same firm.
- Day 5–6: Any other C2 remedials cleared.
- Day 7: Final EIC issued for the new CU; documentation packed.
- Day 8 onwards: Standard void works — clean, decorate, re-let.
The electrical work is on the critical path. Bundling EICR + CU upgrade + any remedials into one mobilisation removes the second visit and tightens the void duration.
CU + EICR combined visit costing
Treating EICR and CU upgrade as one engagement removes a chunk of mobilisation cost:
- EICR per circuit billed at standard portfolio rate.
- CU upgrade priced as one job — fixed for standard 6–8 way RCBO board, quoted on survey for larger or HMO boards.
- Earthing and bonding remedial work (often required at upgrade) priced into the CU quote, not added afterwards.
- No-surprises pricing — the quote is the bill unless the asset manager changes scope.
The cost per property drops by 10–20% when the work is bundled, and the documentation is one chain instead of two.
What to do next
If you’re scoping the CU-upgrade programme for HA stock in the Leeds, Wakefield or Harrogate footprint, JP Electrical & EV Solutions can quote against your void calendar and deliver EICR + CU upgrade in one mobilisation per property. NICEIC-approved, Part P compliant, Leeds-based team, available 24/7 for in-flight C1 finds.
Book a portfolio survey or request a free, no-obligation quote via our housing association electrical services page, or read more about consumer unit installation in Leeds.
FAQ
Does every CU upgrade need to be RCBO-per-circuit?
Not legally — split-load RCD configuration meets BS 7671. For tenanted HA stock, RCBO-per-circuit is recommended because nuisance trips on one circuit don’t black out the rest of the property.
How long does a typical CU upgrade take?
A standard 6–8 way upgrade in an occupied or void property takes a single working day, including the EIC and documentation. HMOs or larger boards can run 1.5–2 days. The property is powered down for portions of the visit, planned with the tenant or void schedule.
Is an SPD required on every new domestic consumer unit?
Under Amendment 2 (BS 7671:2018+A2:2022), SPD is required unless a documented risk assessment supports omission. For HA stock the working standard is to fit SPD as a default — the risk-assessment paperwork to omit it isn’t worth saving the unit cost.