Summary
- Part P requires reasonable provision to protect people from fire and injury from electrical installations in dwellings — delivered in practice through design and installation to BS 7671 (IET Wiring Regulations, 18th Edition as amended).
- Notifiable work (new circuits, consumer unit replacement, work in special locations like bathrooms) must be self-certified by a registered competent person or notified to Building Control with third-party or BC inspection.
- Your PD evidence is the certification trail: Electrical Installation Certificates (EICs) with schedules of test results, and the competent person scheme notification — chase them at handover, because they are near-impossible to recreate later.
What the Building Safety Act requires for Part P on non-HRB domestic jobs
Part P applies to electrical installations in dwellings, including gardens and shared amenities. Every extension and refurbishment includes notifiable electrical work — new circuits for kitchens, showers or EV chargers, consumer unit changes, additions in bath/shower rooms — and the compliance route is binary: a registered competent person (NICEIC, NAPIT, etc.) self-certifies and notifies, or the work goes through Building Control with inspection and testing.
The Principal Designer (BSA) does not design the electrics on most domestic jobs, but the coordination duty still applies: is someone competent designing the installation (not just installing it), does the consumer unit have capacity for the added load (electric showers, heat pumps and EV chargers stack up fast), and will certification actually be delivered? Writing the certification deliverables into the specification is the cheapest compliance instrument available.
Since consumer units must now have non-combustible enclosures and new circuits typically need RCD protection (and increasingly arc fault consideration under BS 7671 Amendment 2), a 'like-for-like' attitude to older installations is a false economy the client should be advised out of, in writing.
Key design risks and evidence needed (RIBA Stages 2–4)
- Stage 2: load check for electrified heating/cooking/EV ambitions against the existing supply (a 60 A single-phase supply will not carry a heat pump, two showers and a 7 kW charger); flag DNO application lead times.
- Stage 3: electrical layout coordinated with joinery and switch/socket height zones (450–1,200 mm, aligning with Part M); bathroom zones defined for special-location compliance.
- Stage 4: specification requiring design, installation and certification to BS 7671:2018+A2:2022; EIC with schedule of test results and scheme notification listed as handover deliverables; smoke/heat alarm interface with Part B specification (BS 5839-6).
Standards and references you should be citing
- BS 7671:2018+A2:2022 — Requirements for Electrical Installations (IET Wiring Regulations, 18th Edition).
- IET Guidance Note 3 — inspection and testing (the basis of the schedules behind an EIC).
- BS 5839-6 — fire detection in dwellings, wired by the electrician but specified by the designer.
- Competent person scheme rules (NICEIC, NAPIT, ELECSA) — the self-certification route for notifiable work.
Notifiable vs non-notifiable domestic electrical work
| Work | Notifiable? | Evidence to log |
|---|---|---|
| New circuit (kitchen, shower, EV charger) | Yes | EIC + scheme notification or BC approval |
| Consumer unit replacement | Yes | EIC + scheme notification |
| New/altered work in bathroom zones | Yes | EIC + scheme notification |
| Adding sockets/lights to existing circuit (outside special locations) | No | Minor works certificate still expected |
| Like-for-like accessory replacement | No | None, but note in project record |
Common pitfalls that catch out sole practitioners
- Completion reached with no EIC because 'the builder's electrician sorted it' — write certification into the contract deliverables and withhold practical completion sign-off until received.
- Supply capacity discovered inadequate after the heat pump and EV charger are ordered; the DNO fuse upgrade or three-phase application should have been a Stage 2 action.
- Certification for the shower circuit but not the consumer unit change done the same day.
- Assuming Part P covers outbuildings' supplies informally run from a garage socket — garden installations are within scope.
Frequently asked questions
What electrical certification should I collect at handover on a domestic job?
An Electrical Installation Certificate (or Minor Works Certificates for small additions) with schedules of inspection and test results to BS 7671, plus the competent person scheme notification confirmation (or Building Control acceptance where that route was used). As PD, store them in the health and safety file / handover pack.
Is replacing a consumer unit notifiable under Part P?
Yes. A consumer unit replacement is notifiable building work, must be certified to BS 7671, and modern units must have non-combustible enclosures. It is one of the most commonly skipped notifications in domestic refurbishment — check for the paperwork.
Track this natively instead of in Word templates
PD Pathway gives small practices an automated Parts A–T relevant-requirements tracker, stage-by-stage Principal Designer checklists and one-click compliance documents — built strictly for non-HRB projects. First project free, then from £10 per project or £99/yr unlimited.