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Frequently Asked Questions (FAQs)


When did Part P come into effect?

Part P came into effect in England and Wales on 1 January 2005.

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What are the requirements of Part P?

As of 1 January 2005 it is a legal requirement for all work on fixed electrical installations in dwellings and associated buildings to comply with relevant standards. The relevant UK standard is BS 7671:2008, Requirements for electrical installations (The IEE Wiring Regulations 17th Edition). BS 7671 covers requirements for design, installation, inspection, testing, verification and certification.

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To what types of electrical work does Part P apply?

  • In or attached to a dwelling
  • In the common parts of buildings serving one or more dwellings, but excluding power supplies to lifts
  • In a building that receives its electricity from a source located within or shared with a dwelling, and
  • In a garden or in or on land associate with a building where the electricity supply is from a source located within or shared with a dwelling

The term dwelling includes houses, maisonettes and flats. It also applies to electrical installations in business premises that share an electricity supply with dwellings, such as shops and public houses with a flat above.

The common parts of buildings includes access areas in blocks of flats such as hallways and shared amenities in blocks of flats such as laundries and gymnasiums.Part P applies to electrical installations located in outbuildings such as detached garages, sheds and greenhouses.Part P applies to parts of electrical installations located on land around dwellings such as garden lighting.

Part P applies to electrical installations that operate at voltages not exceeding 1000 V a.c.Notifiable work includes new installations, house re-wires, and the installation of new circuits. Notifiable work also includes additions to existing circuits in kitchens, bathrooms, outdoors and in other special locations. (See question 5 note 5.)

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Will all electrical work need Building Regulations approval?

No. In general, notification will need to be given to, or full plans deposited with, a building control body only if the work is major involving one or more complete new circuits, and is not being carried out by an electrical contractor registered with an authorised competent person self-certification scheme.

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What types of electrical work are non-notifiable?

The following types of work are non-notifiable:

  • Replacing accessories such as socket-outlets, control switches and ceiling roses
  • Replacing the cable for a single circuit only, where damaged, for example, by fire, rodent or impact (1)
  • Re-fixing or replacing the enclosures of existing installation components (2)
  • Providing mechanical protection to existing fixed installations (3)
  • Installing or upgrading main or supplementary equipotential bonding (4)
  • Work that is not in a kitchen or special location and does not involve a special installation (5) and consists of:
    - adding lighting points (light fittings and switches) to an existing circuit (6)
    - adding socket-outlets and fused spurs to an existing ring or radial circuit (6)


  1. On condition that the replacement cable has the same current-carrying capacity, follows the same route and does not serve more than one sub-circuit through a distribution board;
  2. If the circuits protective measures are unaffected;
  3. If the circuits protective measures and current-carrying capacity of conductors are unaffected by increased thermal insulation;
  4. Such work shall comply with other applicable legislation, such as the Gas Safety (Installation and Use) Regulations;
  5. Special locations and installations are listed below;
  6. Only if the existing circuit protective device is suitable and provides protection for the modified circuit, and other relevant safety provisions are satisfactory.

Special locations and installations (5):

  • Locations containing a bath tub or shower basin
  • Swimming pools or paddling pools
  • Hot air saunas
  • Electric floor or ceiling heating systems
  • Garden lighting or power installations
  • Solar photovoltaic (PV) power supply systems
  • Small scale generators such as micro-CHP units
  • Extra-low voltage lighting installations, other than pre-assembled, CE-marked lighting sets

Note: See Guidance Note 7 which gives more guidance on achieving safe installations where risks to people are greater.

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How will Part P apply to DIY work?

Part P will apply to all electrical work in dwellings, whether carried out by professionals or DIYers.

Some DIY work will require the submission of a building notice to the local authority and the payment of a building control fee. Some minor electrical work will not be notifiable (see above). Examples include adding lighting or powerpoint to an existing circuit, adding a spur to an existing circuit or replacing a light fitting.

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How will compliance with Part P be enforced?

Failure to comply with the Building Regulations is a criminal offence and local authorities have the power to require the removal or alteration of work that does not comply with the requirements.

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What extra costs will be imposed on electricians?

The annual cost of joining a Competent Person Scheme should be negligible when spread over the number of jobs undertaken during the year.

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Local authorities will require more resources to cope with the extra work - where will these come from?

There should be no additional financial implications for local authorities. The money to pay for additional Building Control Inspectors will accrue from building control fees. Some local authorities will employ electrical inspectors, whilst others will operate a system of call-off contracts.

CLG require that the joining and inspection fees set by the scheme operator are sufficient only to cover their costs and allow future development of the schemes.

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Many electrical faults are not caused by bad workmanship, so why bother with Part P?

In the Regulatory Impact Assessment, the Government estimated that around 30% of electrical accidents could be prevented through regulation and that this would justify bringing electrical work in dwellings under Building Regulations control.

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Won't Part P simply drive more work underground?

The Regulatory Impact Assessment considered the question of whether regulation would result in more unsafe work. The Government does not consider there is any evidence that this will be the case.

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What will be the benefits of Part P?

It is expected that bringing electrical work in dwellings under building regulations control will reduce the number of deaths, injuries and fires caused by faults in electrical installations. It is expected that nationally Part P will lead to an improvement in the competence of electrical contractors and to an improvement in the overall quality of electrical work.

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