Domestic Electrical Regulations UK 2026 Part P & BS 7671 Guide
Domestic electrical work in the UK is regulated by Part P of the Building Regulations (England & Wales) and must comply with BS 7671 (IET Wiring Regulations) 18th Edition. Certain electrical work is notifiable — meaning it must be either done by a registered electrician or inspected and certified by Building Control. Understanding these rules is essential for homeowners planning any electrical work.
Part P of the Building Regulations
Part P applies in England and Wales (Scotland has separate regulations under the Building Standards). It requires that electrical installations in dwellings are designed and installed to be safe, and that certain types of work are either done by a Competent Person (registered electrician) or notified to Building Control for inspection. The purpose is to reduce electrical fires and injuries from defective installations. Non-compliance can result in fines, difficulty selling your home, and invalid insurance.
Notifiable vs Non-Notifiable Work
Notifiable work (requires registered electrician or Building Control): New circuits, consumer unit (fuse box) changes, work in bathrooms and kitchens (within zones), work in gardens/outbuildings, addition of socket outlets to kitchens, and any work in a special location (bathroom, swimming pool). Non-notifiable work (DIY permitted): Replacing like-for-like accessories (switches, sockets, light fittings), adding fused spurs to existing circuits outside kitchens/bathrooms, and repair/maintenance work. Important: ALL work, even non-notifiable, must comply with BS 7671.
BS 7671 — The Wiring Regulations
BS 7671 (published by the IET) is the technical standard for electrical installations in the UK. The current edition is the 18th Edition (Amendment 2, 2022). Key requirements include: cable sizing per installation conditions (correction factors for temperature, grouping, insulation), RCD protection for all socket outlets (30mA for additional protection), AFDD (Arc Fault Detection Devices) recommended for certain installations, adequate earthing and bonding throughout, and proper testing and certification of all work. Electricians must follow BS 7671 for all installations.
Competent Person Schemes
Rather than notifying Building Control (which requires inspection and costs £200-300), most electrical work is done by electricians registered with a Competent Person Scheme: NICEIC: The largest and most well-known scheme. NAPIT: Second largest, equally recognized. ELECSA, STROMA, BRE: Other approved schemes. Registration means the electrician is qualified to self-certify their work as compliant with Part P and BS 7671. They issue an Electrical Installation Certificate (EIC) and notify Building Control on your behalf. Always use a registered electrician for notifiable work.
| Type of Work | Notifiable? | Who Can Do It? |
|---|---|---|
| New circuit | Yes | Registered electrician |
| Consumer unit change | Yes | Registered electrician |
| Bathroom electrical work | Yes | Registered electrician |
| Kitchen socket additions | Yes | Registered electrician |
| EV charger installation | Yes | Registered electrician |
| Replace switch/socket | No | DIY permitted |
| Replace light fitting | No | DIY permitted |
| Add fused spur (not kitchen/bath) | No | DIY permitted |
What Homeowners Can Do (DIY)
Homeowners can legally do: Replace like-for-like — swap a broken socket, switch, or light fitting with an identical replacement. Add a fused spur to an existing ring circuit OUTSIDE kitchens and bathrooms. Install outdoor lighting fed from an existing circuit (not a new circuit). Repair damaged cable (junction boxes are acceptable). Homeowners should NOT do: any work involving the consumer unit, new circuits, bathroom or kitchen work, garden or outbuilding circuits, or EV charger installation. When in doubt, hire a registered electrician — the cost is modest compared to the safety risk and legal liability.
Disclaimer: For educational reference only. Consult a licensed professional.