Whenever electrical work is undertaken on domestic premises in England or Wales it must comply with the particular requirements of Part P of the Building Regulations 2010 (England & Wales) as amended. In addition, all other Parts of the Building Regulations relevant to the work must also be satisfied.
Practical guidance on ways to comply with the requirements in the Building Regulations is contained in a series of ‘Approved Documents’ ADs. This article looks at some of the ADs that may be applicable to electrical work.
Separate ADs are published for England and for Wales, covering each of the Parts detailed in Schedule 1 to the Building Regulations 2010 (England & Wales) as amended.
Approved Document A, Structure
The process of electrical installation work in domestic premises generally results in some disturbance to the fabric of the building. For example, to route cables and fix equipment and accessories it may be necessary to lift floorboards, make chases in walls and drill holes through ceilings, walls and joists. Therefore, contractors should comply with the recommendations given in this AD so that when such work is undertaken it does not adversely affect the safety of the property by damaging or weakening building structures or reducing their ability to resist the spread of fire and smoke.
Approved Document B, Fire safety
Among other fire safety recommendations, this AD provides guidance on the provision of fire detection and fire alarm systems for new and materially altered dwellings, including the type and positioning of detectors. The recommendations are generally based on BS 5839-6: 2019, and the installation of one or more smoke alarms should be certificated separately in accordance with BS 5839-6. To minimise the spread of fire and smoke, openings made to install cables, recessed lighting or ventilation fans should be appropriately sealed. For typical domestic premises, a Grade D, Category LD2 system, as shown in below, is the minimum standard recommended for the protection of life against fire. A Practical Guide to Grade D Fire Alarms by Tim Benstead gives more information on BS 5839-6. (Illustration by Alex Whitworth)
Approved Document F, Ventilation
Contractors should have an awareness of the recommendations given in Approved Document F to minimise contravening Part F of the Building Regulations when installing ventilation systems.
The recommendations are intended to provide a healthy environment for the occupants by means of ventilation to regulate humidity, disperse pollutants and hence minimise condensation and mould growth. For these reasons, in a room with no openable window (e.g. an internal room) an intermittent fan should be timed to operate for 15 minutes after being turned off.
This AD is supported by the Domestic Building Services Compliance Guide, which provides minimum recommended performance standards for building services. The following table shows minimum recommended extract ventilation rates for fans for intermittent use (such as those fans mounted in walls, ceilings, windows and cooker hoods), in new dwellings.
Approved Documents L1A & L1B, Conservation of fuel and power
Manage consent Guidance on meeting the requirements of Part L for dwellings is provided by two separate Approved Documents; L1A, applicable to new dwellings and L1B, applicable to existing dwellings (supported by the Domestic Building Services Compliance Guide).
Contractors undertaking electrical work in dwellings generally need to be aware of these recommendations when installing lighting (internal and external), electric heating and heating controls. For example, in the living accommodation of dwellings, three out of four lighting fittings should be of low energy, that is containing lamps with a luminous efficacy greater than 45 lumens per circuit watt, whilst external lighting should be provided with automatic controls to minimise the risk of lights being inadvertently left on.
Approved Document M, Access to and use of Buildings
Approved Document M recommends appropriate mounting heights for light switches, socket outlets and other equipment to assist those people whose reach is limited to use the dwelling more easily.
For new dwellings, this can be achieved by wall-mounting electrical equipment in habitable rooms at between 450 mm and 1200 mm above the finished floor level and mounting consumer units so that the switches are between 1350 and 1450 mm above the finished floor level.
Approved Documents and associated guidance for England, Wales, Scotland and Northern Ireland are subject to change so it is your responsibility that reference is made to the relevant current documents.