Part P applies to all fixed installations. The requirement applies to all fixed electrical installation work in dwellings, whether carried out professionally or by DIY, whether or not minor work, and whether or not the work is notifiable to a building control body. However, certain relaxations may apply for the inspection, testing and certification of minor work undertaken as DIY.

Part P will apply to all fixed installations after the supplier's meter in buildings or parts of buildings comprising:

• Dwellings
• Combined dwellings and business premises having a common supply (such as shops, pubs etc)
• Common access areas in blocks of flats (but not lifts)
• Shared amenities in blocks of flats (such as laundries, gymnasiums etc)
• Outbuildings, including sheds, garages and greenhouses○ Garden lighting and power supplies

Part-P Requirements

As of 1/1/2005 Part P of the building regulations was introduced by the office of the deputy prime minister.

Fixed electrical installations in dwellings shall be suitably designed, installed, inspected and tested so as to provide reasonable protection against their being a source of a fire or a cause of injury to persons.The requirement applies only to fixed electrical installations in dwellings in England and Wales intended to operate at low voltage or extra-low voltage.

Parts of fixed electrical installations external to premises, such as in gardens, sheds, detached garages and the like, will also be subject to the requirements of Part P. The safety requirement will be applicable to alterations and additions to existing installations (including rewires), as well as to new construction. There will be a requirement to ensure that parts of an existing installation upon which new work depends for safety (such as the earthing and bonding arrangement) comply with the requirements of BS 7671:2011. This requirement for consequential remedial work is a departure from the normal Building Regulations approach.