Part P Building Regulations Explained for Homeowners
Updated: Oct 9
In England, electrical work in homes falls under Part P of the Building Regulations. Part P requires electrical installations to be designed and installed so that people using, maintaining or altering them are protected from fire and injury, and it makes three kinds of work notifiable: installing a new circuit, replacing a consumer unit, and any addition or alteration to circuits in a special location such as the zones around a bath or shower. Notifiable work must be certified, usually by a registered electrician who self-certifies it, otherwise through a third-party certifier or building control.
Everything else, from swapping a light fitting to adding a socket to an existing kitchen circuit, still has to be done safely, but nobody has to be told about it.
What does Part P actually say?
The legal requirement is one sentence, Requirement P1 of the Building Regulations 2010: "Reasonable provision shall be made in the design and installation of electrical installations in order to protect persons operating, maintaining or altering the installations from fire or injury." The government's guidance on meeting it is Approved Document P (the 2013 edition, still current), which points to BS 7671, the IET Wiring Regulations, and sets out which work is notifiable and how it is certified.
Where does Part P apply?
Part P covers the electrics in houses and flats in England, including outside lights, garden lighting and pond pumps, outbuildings such as sheds and detached garages, the common parts of blocks of flats, and a shop or pub on the same meter as a dwelling. It does not cover separately metered business premises or the supply to lifts in blocks of flats. Wales, Scotland and Northern Ireland have their own rules, so this post covers England.
What electrical work is notifiable?
Regulation 12(6A) of the Building Regulations 2010 sets out the full list:
the installation of a new circuit
the replacement of a consumer unit
any addition or alteration to existing circuits in a special location
A special location is defined in regulation 12(9) as either:
within a room containing a bath or shower, the space around the bath tap or shower head, extending from the finished floor up to 2.25 metres (or up to the shower head if it is fixed higher), and horizontally 0.6 metres from the edge of the bath or shower tray, or, where there is no tray, 1.2 metres from the centre of the shower head; or
a room containing a swimming pool or sauna heater.
That is the whole list; Electrical Safety First notes the April 2013 changes narrowed it, removing some requirements for kitchens and outdoor spaces. It is also why every house rewire is notifiable: it installs new circuits and almost always replaces the consumer unit, on top of the other rewiring regulations it has to meet.
Other everyday notifiable jobs include a new circuit for an electric shower, cooker, EV charger or outside sockets, a new supply out to a garage or shed, a new circuit to an electric gate isolator, and adding or moving a light or extractor fan within the bathroom zones.
What electrical work is not notifiable?
Approved Document P puts it simply: everything not in regulation 12(6A) is not notifiable, "namely additions and alterations to existing installations outside special locations, and replacements, repairs and maintenance anywhere." That covers:
replacing a socket, switch, ceiling rose or light fitting like-for-like, anywhere
adding a socket or light point to an existing circuit, outside the bathroom zones
repairing or replacing a damaged cable on an existing circuit
installing a built-in cooker on an existing cooker circuit
connecting an electric gate or garage door to an existing isolator
Non-notifiable doesn't mean unregulated. Approved Document P says this work should still be designed, installed, inspected, tested and certificated to BS 7671, and local authorities can take enforcement action if they find it unsafe.
Do you need building regs to add a socket?
Not if you're extending an existing circuit, such as a kitchen ring or a bedroom radial, outside a special location. It still has to meet BS 7671, which includes 30 mA RCD protection for most sockets, so on an older installation without RCDs a simple extra socket can raise a bigger question. A socket on a new circuit is notifiable, and ordinary sockets don't belong near a bath or shower at all: BS 7671 (regulation 701.512.3) does not allow a socket, other than a shaver supply unit or a SELV socket, within 2.5 metres horizontally of the boundary of zone 1.
The three ways to certify notifiable work
Approved Document P sets out three routes:
Self-certification by a registered competent person. The electrician is registered with a government-authorised competent person scheme. They issue a BS 7671 Electrical Installation Certificate, and within 30 days of completion the installer or their scheme must give you a Building Regulations compliance certificate and tell building control.
Third-party certification. An installer who isn't registered appoints a registered third-party certifier before work starts and notifies them within 5 days of finishing. The certifier inspects and tests, and the compliance certificate follows within 30 days of a satisfactory report.
Building control. The installer notifies a building control body before work begins. Building control decides what inspection and testing it needs, charges a fee, and issues a completion or final certificate once satisfied.
Route 1 is the simplest, because the electrician handles the notification and you deal with nobody else.
Can you do your own electrical work?
Non-notifiable work can legally be done by a homeowner, provided it meets BS 7671; the real limit is whether you can do it safely and test it. Notifiable work doesn't have to be done by an electrician, but it must be certified, so a homeowner has to notify building control before starting, pay the fee and pass their inspection and testing. For a consumer unit or a new circuit that is slow, and failing inspection means paying to put it right.
What paperwork should you receive?
After notifiable work by a registered electrician you should have an Electrical Installation Certificate with test results and a schedule of circuits, the Building Regulations compliance certificate, and labels at the board and on earthing connections, which Approved Document P also expects. Small non-notifiable jobs usually get a Minor Electrical Installation Works Certificate; our guide to electrical certificates sets the documents side by side. Keep them all: a buyer's solicitor will ask for them when you sell.
What if work wasn't certified?
Gov.uk sets out the risks: the person doing the work can be prosecuted and fined, building control can make you pay to fix faulty work, and you won't have the certificates you may need when you sell. If work has already been done without notification, ask your local building control about regularising it.
Does adding to an old installation mean upgrading everything?
No. Approved Document P says only the new work has to meet current standards, unless it would make the existing installation less safe or the existing installation's condition means the new work can't be used safely. The installer should still check that existing equipment, including the network operator's, can carry the extra load, and that protection, earthing and bonding are adequate. That check is often where an old board shows its age: if yours has rewireable fuses or no RCD protection, a consumer unit upgrade may be needed before a new circuit can be added safely.
SM Electrical is registered with a Competent Person Scheme, so we self-certify notifiable work across Shropshire, Wolverhampton and the West Midlands, from rewires and board changes to new circuits for EV chargers, showers and outdoor power. If you're not sure whether a job needs notifying, ask us before you start.
Part P questions, answered
How do I check an electrician can self-certify?
Ask which competent person scheme they're registered with, then look them up on the electrical Competent Person Register, which gov.uk describes as the single place for householders to find registered electricians.
When does building control need to see the work?
On the building control route, they may want to inspect cables before walls are plastered, which is the gap between first fix and second fix electrics.
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