Also see:
8.68.1.6 Electrical services
Electrical installations shall be provided in accordance with relevant regulations, codes and standards. The installation shall ensure safe and satisfactory operation and be protected from chemical attack.
Items to be taken into account include:
- installation
- provision of sockets
- cable positions
- consumer units
- fire rated partitions
- lighting outlets
- cooking spaces
- built-in appliances
- metal splashbacks
- electrical supply to gas appliances
- TV
- smoke alarms
- electric vehicle charging points
- electronic communications
- lightning protection.
8.1.6.1 Installation#
Electrical services and installations should:
- comply with BS 7671 ‘Requirements for electrical installations’
- comply with BS 6004 ‘Electric cables. PVC insulated and PVC sheathed cables for voltages up to and including 300/500 V, for electric power and lighting’
- have fittings and components located in accordance with relevant Building Regulations
- be installed in accordance with the manufacturer’s recommendations
- ensure cables are not placed under, against or within thermal insulation, unless they have been appropriately sized and derated
- ensure PVC covered cables are not in contact with polystyrene insulation
- be provided with a completion certificate by the electrical contractor to the builder. This certificate to cover all aspects of the installation, including earth bonding
- be earthed, where electrical sockets, fused spurs or light switches use metal back boxes that are fully recessed and covered by the faceplate. The earth terminal on the sockets should be used to connect the earth wire to. If no earth terminal is provided as in the case of a light switch the metal back box requires earthing
- not leave exposed wiring for homeowners to connect their own electrical fittings after occupation. All cables should terminate in a suitable proprietary electrical enclosure complying with the appropriate British Standard such as a recessed back box with cover or a temporary light fitting eg batten lamp holder as appropriate
- incorporate appropriate automatic devices for protection against overcurrent or leakage. Where electrical items contain electronic components or create a Direct Current (DC) waveform in an Alternating Current (AC) supply then the RCD should be a suitable type to prevent nuisance tripping eg heat pumps, solar photo voltaic, micro wind, electric vehicle charging points, circulating pumps or induction hobs, USB charging sockets
- be supported such that they will not be liable to premature collapse in the event of a fire. This can be achieved by using steel containment systems (either in or on) and precludes the use of non-metallic cable clips or ties as the sole means of support where cables are clipped direct to exposed surfaces. Suitably placed steel or copper clips, saddles would be acceptable. (Plastic rawlplugs with a steel clip will be acceptable if suitably sized for the screw and load)
- be sited to provide reasonable access to homeowners as shown in table 5.
Table 3: Minimum height of switches/sockets and controls
| Region | Height of switches/sockets & controls above floor level |
|---|---|
| England Approved Document M1 | 450mm - 1200mm |
| Wales Approved Document M1 | 450mm - 1200mm |
| Scotland Technical Handbook 4.8.5 | 400mm - 1100mm |
| Northern Ireland Technical Booklet R | 400mm - 1200mm |
8.1.6.2 Provision of sockets#
Rooms should be provided with the minimum number of 13A outlets listed in Table 4 (dual outlets count as two).
Table 4: Minimum number of outlets
| Room | Outlets | Notes |
|---|---|---|
| Kitchen/utility | 8 | Where homes have separate areas, the kitchen should have a minimum of four outlets and the utility room four. Where appliances are provided, a minimum of three outlets should be free for general use. Located above the worktop level |
| Living or family room | 8 | A minimum of two outlets near the TV aerial outlet |
| Bedrooms | 6 (4) | A minimum of six outlets for the main bedroom and a minimum of four outlets for other bedrooms |
| Dining room | 4 | |
| Landing | 2 | |
| Hall | 2 |
8.1.6.3 Cables positions#
Cables without special protection, such as an earthed metal conduit, should be positioned:
- vertically or horizontally from the outlet or switch being served
- within the shaded zone in the diagram. See figure 10 or
- a minimum of 50mm from the surface of a wall, or a minimum of 50mm from the top or bottom of a timber joist or batten in a floor or ceiling.
Where the position of switches or sockets can be determined from the reverse side of the wall or partition, the zone on one side of the wall or partition applies to the reverse side.
8.1.6.4 Consumer units#
Consumer units should:
- have their enclosure manufactured from non-combustible material or be enclosed in a cabinet or enclosure constructed of non-combustible material (ferrous metal eg steel, is deemed to be an example of non-combustible material)
- be compliant with BS EN IEC 61439-3 and where installed for use by ordinary persons have an IP 2XC rating
- not have any gaps between blanking pieces and circuit breakers larger than IPX2C requirement (hazardous parts within the enclosure cannot be contacted by a wire probe 2.5mm diameter and 100mm long)
- provide space for the installation and subsequent repair or replacement in line with manufacturer’s recommendations
- be sited to provide reasonable access to homeowners as shown in table 5.
Table 5: Minimum height of consumer units
| Region | Minimum height of consumer units above floor level |
|---|---|
| England Approved Document M4(2) | 1350mm - 1450mm |
| Wales Approved Document M1 | 1200mm - 1400mm |
| Scotland Technical Handbook 4.8.5 | 900mm - 1200mm |
| Northern Ireland Technical Booklet R | Based on controls 1200mm - 1400mm |
- where multiple rows of consumer units are utilised BEAMA recommend the bottom row of switches located 1350mm – 1450mm
- be sited to provide reasonable access for consumers, a minimum of 300mm to an internal corner (measured to the centre line of the socket or switch)
- be labelled such that each circuit protected by a fuse or circuit breaker can easily be identified
- where labels/notices are not provided the Electrical Installation Certificate, complete with guidance for recipients as detailed in appendix 6 of the IET wiring regulations should be made available for inspection on site
- where labels/notices are fitted they should be fixed in a permanent position at or near the origin of every installation. The most convenient location for these notices is usually on the consumer unit. Any notice should be of a durable material and indelibly marked. See figure 11.
- Have a minimum of 300mm measured horizontally to the edge of any bowl of a sink or wash basin opening to avoid splashing from the sink or basin. General guidance is to avoid positioning a consumer unit immediately above or alongside a sink and where space exists an accessory should be located beyond the drainer. See figure 12.
8.1.6.5 Fire rated partitions#
Electrical installations installed in fire rated partitions should:
- comply with the requirements for cable, conduits, sockets and provision as specified in BS 7671
- not impair the fire resistance of the structure to any means of escape. The provision of any electrical item must maintain the integrity of the compartmentation of the original building design
- where intumescent pads (putty pads) or lined backing boxes are used, they should hold satisfactory assessment, in accordance with R3a ii, have an appropriate period of fire resistance, be suitable for the intended application and be used in accordance with the manufacturer’s recommendations.
8.1.6.6 Lighting outlets#
Lighting outlets should be provided:
- in each room, hall, landing and staircases
- with two-way switching at each floor level in a staircase
- in the common areas of homes and controlled by either manual switching or automatic light-sensitive controls.
8.1.6.7 Cooking spaces#
Cooking spaces should:
- have a minimum 30A supply which is suitably switched and terminated
- have a 13A socket outlet where there is a gas supply
- where provided, have cooker panels located to the side of the cooker space
- have a minimum of 100mm measured horizontally from an electrical accessory to the edge of a freestanding cooker or individual hob. See figure 13.
8.1.6.8 Built-in appliances#
Where appliances are built in:
- isolation should be reasonably accessible and in compliance with the manufacturer’s recommendations
- disconnection points should always be local to the appliance to enable isolation without affecting the use of other electrical appliances or equipment in the same circuit
- disconnection should not require the removal of the appliance from its housing to access and operate.
8.1.6.9 Metal splashbacks#
The Institute of Electrical Engineers have confirmed that earth bonding is not required to metal splashbacks in kitchens including those splashbacks containing electrical accessories such as socket outlets.
8.1.6.10 Electrical supply to gas appliancesAlso see:
8.3.2.7#
Where a gas appliance requires an electrical supply, a suitable fixed spur or socket outlet should be provided.
8.1.6.11 TV#
Aerials are not required; however, one of the following should be provided:
- a concealed, coaxial cable from the roof void to a terminal outlet in the main living room
- a conduit and draw wire or suitable alternative.
8.1.6.12 Smoke alarms#
Smoke alarms should be installed within loft spaces where electrical equipment is present ie, solar PV, inverters, batteries or boilers. Where smoke alarms are required they should comply with BS 5839-6 and have a mains power supply from either:
- an independent circuit with no other electrical equipment connected other than a dedicated social alarm control unit or a mains powered carbon monoxide alarm (CO) interlinked if the manufacturer’s instructions allow this
- a separately electrically protected regularly used lighting circuit in which case there should be a means of isolating the smoke alarm from the lighting circuit for maintenance.
If more than one smoke alarm is interconnected, then they should all be isolated by one single circuit (unless the interconnection is via remote communication).
Where used smoke alarms should be labelled appropriately to prevent the device being inadvertently disconnected. Labels should be:
- provided to any isolator stating, “smoke alarm is fitted do z provided to any lighting circuit isolator stating, “caution not switch off”
- provided to any lighting circuit isolator stating, “caution not switch off” smoke alarms connected to this circuit do not switch off”.
8.1.6.13 Electric vehicle charging points#
Where electric vehicle charging points are installed considerations should be given to:
- technical requirements
- product certification
- operative competency
- manufacturer’s instructions
- location to not cause hazard or nuisance
- serviceability.
8.1.6.14 Electronic communications#
Where electronic communications are installed considerations should be given to:
- technical requirements
- distribution point
- common access point
- public electronic communications networks.
8.1.6.15 Lightning Protection#
Lightning protection where used should comply with the relevant standards and be appropriate for the location installed:
| BS EN 62305-1-5 | Protection against lightning |
| PD 62305-2: 2014 | Flash density map 2014. Supplement to BS EN 62305-2 |
| BS EN IEC 62561-1 | Lightning protection system components |
| BS EN IEC 62561-2 | Lightning protection system components |
| IEC 60068-2-52 | Environmental testing: Salt mist, cyclic (sodium chloride solution) |
| IECISO 6957 | Copper alloys: ammonia tests for stress corrosion resistance |
| ISO 22479 | Corrosion of metals and alloys – sulfur dioxide test in a humid atmosphere |
Last updated: 2nd January 2024