Part P and DIY Electrical Work: What You Can Do and What You Must Notify

Electricity is the one DIY area where a small mistake can kill someone months after the work is finished. A loose terminal, an unprotected cable or a missing earth can sit hidden behind plaster until the day it causes a fire or a shock. That is the reason the Building Regulations in England include a dedicated section on electrical safety in dwellings, known as Part P. Homeowners often hear that you are “not allowed” to do your own wiring. That is not quite right, and the real position is more useful to understand: you may do much of the work yourself, but some jobs must be notified to building control or signed off by a registered electrician, and all of it must be safe and meet the wiring standard, BS 7671.

What Part P actually says

Part P of Schedule 1 to the Building Regulations 2010 requires that reasonable provision is made to protect people from fire or injury caused by electrical installations in dwellings. The associated statutory guidance, Approved Document P (2013 edition, published January 2013), sets out how to meet that requirement. It applies to electrical installations in homes and in their immediate surroundings such as gardens, garages and outbuildings that are served from the dwelling’s supply, and to parts of a building shared with a dwelling, such as a communal hallway. Part P is law in England. Wales has its own version of the Building Regulations and guidance, so if you are in Wales, check the Welsh Government’s Approved Document P rather than assuming the English position. Scotland operates under building standards with a building warrant system, and Northern Ireland has separate regulations; the rules below should not be assumed to apply there.

Notifiable and non-notifiable work

The 2013 edition reduced the range of electrical work that must be notified. In broad terms in England:

• Notifiable: installing a new circuit (for example a new cooker, shower or EV charger supply, or a new ring or lighting circuit), and replacing a consumer unit (fuse board). Many homeowners are surprised that swapping the consumer unit counts.
• Generally not notifiable: replacing accessories such as sockets, switches and light fittings like for like; replacing a damaged cable for part of a circuit; adding a socket or light point to an existing circuit in an ordinary room; repairs and maintenance. These are still electrical work, and must still be safe and comply with BS 7671, but they do not need to be notified.

Some locations, such as bathrooms, swimming pools and saunas, have extra requirements under BS 7671 for special locations (zones around the bath and shower). Whether a particular job in a special location is notifiable has changed between editions of the guidance, so confirm with your local authority building control team before you start. This article gives the general picture, not a definitive ruling on any one job.

Your options when work is notifiable

1. Use a registered competent person. An electrician registered with a government-authorised Competent Person Scheme (such as NICEIC or NAPIT) can self-certify the work, notify building control on your behalf through the scheme, and issue a certificate. This is the simplest route and the one most homeowners take. Check the register online and ask for the registration number.
2. Use a registered third-party certifier. If you do the work yourself or use a non-registered electrician, Approved Document P allows a registered third-party certifier to inspect and test the work and then sign it off. They charge for this, and you must arrange it before the work is covered up, as they need to see the installation at the appropriate stages.
3. Submit a building notice or full plans to your local authority. Building control inspects the work, or arranges for an electrical inspector to do so. Fees apply and vary by council.

What you cannot safely do is complete notifiable work, say nothing, and hope. The local authority can require work to be opened up for inspection, and in serious cases enforcement action can follow. In practice, the more common problem arises later: a buyer’s solicitor asks for the Building Regulations completion certificate or electrical installation certificate, you do not have one, and the sale stalls. Indemnity insurance does not make the installation safe.

Certificates you should know about

Landlords in England must have the electrical installations in rented homes inspected and tested at intervals of no more than five years under the Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020. That is separate from Part P but is part of why EICRs are common.

Can you really do it yourself?

Legally, yes, subject to notification. Practically, the question is whether you have the knowledge and test equipment to do it safely. Safe isolation is the first test: you must prove a circuit is dead using an approved voltage indicator (and prove the indicator on a known live source), and lock off the isolator. A non-contact tester alone is not enough. After the work, an installation needs more than a visual check. Electricians carry out continuity of protective conductors, insulation resistance, polarity, earth fault loop impedance and RCD tests, and record the results. If you do not own, and know how to use, a proper multifunction tester, you cannot verify that your own work is safe, however neat it looks.

A sensible split for the careful DIYer is to do the preparatory and finishing work (chasing walls, fitting back boxes, running cable under the electrician’s direction, plastering and decorating) and leave connection, consumer unit work and testing to a registered electrician. This lowers the cost without compromising safety. If you plan to do notifiable work yourself, speak to building control or a third-party certifier first so they can tell you what they need to inspect and when.

Key technical points the regulations care about

• Cable sizing and protection. The cable must carry the load without overheating and the overcurrent device must protect it. Voltage drop must be limited. Use the BS 7671 cable size and voltage drop calculator as a check, not a substitute for design.
• RCD protection. Under BS 7671:2018 and its amendments, most socket outlets rated up to 32 A for general use, and circuits in bathrooms, need 30 mA RCD protection. Cables concealed in walls less than 50 mm deep, without mechanical protection, also need RCD protection. A modern consumer unit usually has RCBOs or RCD-protected ways to achieve this.
• Consumer unit materials. Domestic consumer units installed in England must be made of non-combustible material or enclosed in a non-combustible enclosure, following Amendment 3 to BS 7671 in 2015.
• Earthing and bonding. Main protective bonding to metal gas and water pipes must be checked. Replacing a consumer unit is a common time to discover inadequate earthing.
• Cable routes (safe zones). Cables should run horizontally or vertically from accessories, or be otherwise protected, so that nobody drills into one by accident.
• Supplementary equipotential bonding and special locations. Bathroom zones restrict the equipment allowed and its IP rating.

Common jobs, and where they fall

• Replacing a ceiling rose or light fitting: generally not notifiable; isolate and be sure of the earth connection and the fire rating of recessed lights near insulation (see our loft insulation guide).
• Adding a spur socket: generally not notifiable if it is an extension of an existing circuit and the circuit can safely supply it, but the circuit protection, cable and RCD must be right.
• Installing an electric shower: normally a new circuit, so notifiable.
• Fitting an electric vehicle charger: a new dedicated circuit, so notifiable; see our EV charger guide and the EV charger circuit calculator.
• Connecting solar panels or batteries: a generating installation needing notification to the network operator as well as Part P (see the solar panel guide).
• Installing a garden shed or garage supply: new circuit with buried armoured cable and appropriate protection; notifiable. If you are building the shed itself, our shed base guide covers the foundation.

Which standard applies?

BS 7671, the IET Wiring Regulations, is the technical standard that Approved Document P points to. The 18th Edition appeared in 2018 and has been amended since; amendments come into effect on dates set by the IET and BSI, with a transition period before the previous version is withdrawn. Because that timetable moves, check the IET website for the current amendment before you buy a book or begin a design. A competent registered electrician will already be working to the right version.

When to get a professional

Call a registered electrician for consumer unit replacement, any new circuit, rewiring, anything involving the incoming supply, work in special locations if you are unsure, and any time you find old or damaged wiring, aluminium cable, or signs of burning. Ask for an EIC and keep it with your property documents. If you are unsure whether a job is notifiable, phone your local authority’s building control team before starting; most will answer a short question for free. Our overview of which projects need building regulations approval puts Part P in the wider context.

This is general information, not legal or professional advice. Rules differ between England, Wales, Scotland and Northern Ireland, and guidance is updated, so confirm the current position for your own project.

Sources

• Planning Portal: Approved Document P Electrical safety
• GOV.UK: Electrical safety - Approved Document P
• The Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020
• IET: BS 7671 Wiring Regulations