L at home

Amendments to Part L of the Building Regulations (Conservation of fuel and power) came into force in England and Wales on 6 April 2006. These introduce new energy efficiency requirements as part of the government's drive to reduce greenhouse gas emissions by improving the energy efficiency of buildings.

Part L is divided into four Approved Documents covering the design and construction process for all buildings.

The new requirements for fixed electrical installations in new and existing dwellings are covered in Approved Documents L1A and L1B, respectively.

The systems covered

The Regulations under which the Approved Documents are issued require reasonable provision to be made for the conservation of fuel and power in buildings by:

• limiting heat gain and losses through thermal elements and the building fabric, and from pipes, ducts and vessels used for space heating, cooling and hot water storage;
• providing and commissioning energy efficient fixed building services with effective controls;
• providing the owner with sufficient information about the building, its fixed m&e services and their maintenance so that it can be operated and maintained efficiently in terms of fuel and power use.

Fixed electrical installations covered by the documents include any part of:

• fixed internal or external lighting installations, excluding emergency escape or specialist process lighting;
• electric heating or hot water services;
• any controls associated with the above lighting or heating installations.

Meeting Part L1A

Approved Document L1A covers all new dwellings except for buildings containing rooms for residential purposes, such as nursing homes, student accommodation and similar. The presence of a small flat for a member of staff or an in-house manager in a non-domestic building would not result in the whole building being treated as a dwelling.

The actual Approved Documents contain five main criteria to be considered. The main changes that affect electrical services follow.

Fixed internal lighting

A way of showing compliance is to provide light fittings - including lamp, controlgear and an appropriate device for controlling the light output, such as housing, reflector, shade or diffuser - that only take lamps with a luminous efficacy greater than 40 lumens/circuit-watt: circuit-watts being the power consumed in a circuit by lamps and their associated controlgear and power factor correction equipment.

Fluorescent and most compact fluorescent luminaires would meet this standard. Luminaires for GLS tungsten lamps or tungsten halogen lamps would not.

Reasonable provision would be to install fixed energy efficient light fittings in the most frequented areas to a number at least:

• one per 25 m2 of dwelling floor area or part thereof (excluding garages); or
• one per four fixed fittings.

Installing mains frequency fluorescent lighting in garages or workshops may cause dangers through stroboscopic interaction with engines or tools. High-frequency electronic ballasted fluorescent lamps substantially reduce this risk.

However, garages will normally be excluded from the areas where energy efficient lighting can count towards the total since they are not heated. Light fittings in low frequented areas like cupboards and other storage areas also do not count. The Energy Saving Trust's GIL20: Low energy domestic lighting gives guidance on identifying suitable locations.

External lighting

Fixed external lighting refers to that fitted to an exterior surface of a dwelling and supplied from the occupier's electrical system. It excludes the lighting in common areas in blocks of flats and other communally provided access lighting.

Reasonable provision in this case would be to enable effective control and/or the use of efficient lamps such that:

• lamp capacity does not exceed 150 W per fitting and the lighting automatically switches off when there is enough daylight and it is not required at night; or
• the fittings have sockets that can only be used with lamps with an efficacy of over 40 lumens/circuit-watt.

Compact fluorescent lamps would meet the standard in the second case above where the fittings restrict the type of lamp used. GLS tungsten lamps with bayonet cap or Edison screw bases; or tungsten halogen lamps would not. This is all pretty self-explanatory, although in fact not all compact fluorescent lamps give 40 lumens/W.

Also, from April 2006 fixed external lighting will come within the scope of the Clean Neighbourhoods and Environment Act 2005, with regards to light pollution. Lighting is being included in the Act as a factor that can be a "statutory nuisance".

Space and water heaters

Guidance given in this section of the Approved Document covers the following types of electrical heating installations:

• boilers for central heating systems;
• panel heaters;
• warm air heaters;
• storage heaters;
• fan, convector and radiant heaters;
• underfloor heating systems.

These may be used to provide primary or secondary space heating in dwellings. The electrical hot water heaters covered are:

• point-of-use systems;
• instantaneous systems;
• local systems;
• centralised systems.

Under the Regulations, a reasonable provision for the performance of heating and hot water system(s) would be:

• the use of an appliance with an efficiency at least that recommended for its type in the Domestic Heating Compliance Guide; and
• the provision of controls that meet the minimum requirements given in the Domestic Heating Compliance Guide for the particular type of appliance and heat distribution system being used.

Heating and hot water systems should be commissioned so that on project completion they work as intended and can operate efficiently for the purposes of conserving fuel and power.

In order to demonstrate that the systems have been adequately commissioned, Regulation 20C states:

• where this regulation applies, the person carrying out the work shall give notice to the local authority confirming that the services have been commissioned in accordance with a procedure approved by the Secretary of State;
• the notice shall be given to the local authority no later than the date on which it is required under Regulation 15(4); or not more than 30 days after completion of the work.

This Regulation applies to building work in relation to paragraph L1(b) of Schedule 1, which imposes a requirement. It does not apply where the work consists only of work described in Schedule 2B.

Part L1B explained

Approved Document L1B covers existing dwellings and gives guidance relating to:

• extensions;
• the creation of a new dwelling or part of a dwelling through a material change of use;
• material alterations to existing dwellings;
• the provision of a controlled fitting;
• the provision or extension of a controlled service;
• the provision or renovation of a thermal element.

In most cases, a reasonable provision to meet the Regulations would be to limit the area of windows, roof lights and doors in extensions so that they do not exceed 25% of the floor area of the extension plus

the area of any windows or doors which, as a result of the construction works undertaken, no longer exist or are no longer exposed to the external environment.

In some cases different approaches may be adopted by agreement with the building control body in order to achieve a satisfactory level of daylighting. Guidance for this can be found in BS 8206-2 Code of Practice for Daylighting.

Installation requirements

In the case of fixed internal lighting, the requirements are the same as for new dwellings. These kick in when:

• a dwelling is extended;
• a new dwelling is created from a material change of use;
• an existing lighting system is being replaced as part of rewiring works.

In terms of the installation of fixed external lighting, electrical space heating and hot water heaters the requirements are the same as with Part L1A for new dwellings.

Operating instructions

In accordance with L1(c), the building owner should be provided with sufficient information about the property, its fixed services and their maintenance requirements so that it can be operated to use no more fuel and power than is reasonable in the circumstances.

One way of complying would be to provide an easily understandable set of operating and maintenance instructions aimed at achieving economy in the use of fuel and power.

The instructions should be directly related to the systems installed. This information will eventually form part of the Home Information Pack.

Electronic versions of a checklist of the evidence that could be compiled to demonstrate compliance can be downloaded from the Department for Communities and Local Government website below.

Competent persons

New fixed electrical installation work in dwellings should be carried out and notified by firms registered with a Competent Person Scheme, unless the work is inspected and certified by the local Building Control office.

The existing Part P (Electrical safety) competent persons schemes have been modified to include the Part L requirements to enable registered firms to self-certify that their new electrical work complies with the Building Regulations. Further information on Part P Competent Person Schemes can be found at the website below.