Building Regulations

Building Regulations – Energy Efficiency Requirements of Lighting

Part L of the Building Regulations 2000 as amended October 2001 for England and Wales, Part J of the Building Standards in Scotland as amended March 2002. In both cases, the aim of the regulations is to improve the overall energy efficiency of lighting installations without limiting the quality of lighting design.

The lighting regulations for compliance with Part L are divided into two sections:
L1(c) for dwellings
L2(g) for buildings or parts of buildings other than dwellings.

Part L1, Dwellings:
Internal lighting
Section 1.54 of the Approved Document to L1 requires that reasonable provision be made for the installation of energy efficient lighting, preferably in those areas where the lighting is expected to have most use. To achieve this it recommends the installation of at least the following number of light fittings, which will only take lamps having a luminous efficiency greater than 40 lumens per circuit-watt.

External lighting (fixed to building)
This includes lighting in porches, but not in garages or carports. The recommendation is that all external lighting should automatically switch off when there is enough daylight (or when they are not needed at night) and that these light fittings can only be used with lamps that have a luminous efficiency greater than 40 lumens per circuit-watt.

Part L2, Buildings or parts of buildings other than dwellings.
L2(g) covers those with a floor area of over 100m2; the requirement is to provide lighting systems that are energy efficient, have the opportunity for good energy management and have been properly commissioned.

We can provide further information on how to meet these guidelines. Note that L2 also applies when replacing or renovating old lighting systems in over 100m² of floor area.

Appendix F: Meeting the lighting standards
General lighting in office, industrial and storage buildings can be designed to meet the regulations by selection of lamp and luminaire types.

F1 The performance standard for the electric lighting system in these building types depends on the efficiencies of both the lamp/ballast combination and the light fitting.

The recommendation in paragraph 1.43 is met if:

The installed lighting capacity in circuit Watts comprises lighting fittings incorporating lamps of the following type and all the luminaires have a light output ratio of at least 0.6.

High efficiency lamps for non-daylit areas of offices, industrial and storage buildings
High pressure sodium: All ratings above 70W
Metal halide: All ratings above 70W
Fluorescent Tubes: All 26mm diameter (T8) lamps and 16mm diameter (T5) lamps rated above 11W, provided with low-loss or high frequency control gear.
Compact fluorescent: All ratings above 26W

A maximum of 500W of installed lighting in the building is exempt from the above requirement
Note that these standards also apply when replacing or renovating old lighting systems in over 100m² of floor area. These regulations do not apply to building types included in Purpose Group 1, dwellings.


Lighting Guide 3 (LG3) and Lighting Guide 7 (LG7): Office and workplace lighting

LG3 relates to the visual environment for display screen use. This could be anywhere that VDT’s and PC monitors are in operation, not just offices. In 2001 CIBSE (Chartered Institute of Building Services Engineers) introduced an addendum to LG3, the reason for this was that a small section in the guidance with regard to cut-off control was being adopted as compliance with the standard. In practical terms this meant an awful lot of schemes used only Category 2 (Cat2) luminaires as a way to comply with LG3. Clearly, just using a Cat2 luminaire was never meant to ensure compliance.

Partly because of this reason an addendum was introduced that addressed several issues that had arisen since the introduction of LG3 including; the changes in screen and software technology, cut-off control guidelines, ceiling and wall illumination. These are all important factors in creating a good lighting scheme.

In contrast, LG7 (2004) is a specific lighting guidance for offices that replaces the old LG7 that dates from 1993. The need for the update was largely due to the fact that design trends have moved on and to place more emphasis on the visual environment. It was recognised that solely using numerical criteria to define what constitutes a pleasantly lit space was not possible as so much depends on room size, décor, layout and other factors. It also makes clear that the recommendation for ceiling illuminance to be around 30% of the average working plane illuminance was meant to achieve lit spaces that are pleasant to occupy – not just as a criteria for pass or fail. Taken as a whole LG7 lays down good practice, advice and standards for office lighting design whilst also putting this ‘flesh on the bones’ of the LG3 Addendum, so to speak.

Fire Rated Downlights & the Building Regulations in the UK

Document B, England & Wales; Technical Handbook No:2, Scotland; and Technical Booklet E, Northern Ireland
Demands that if a fire resistant element e.g. a ceiling protecting an upper floor, is broken into to install services, such as recessed spotlights, the fire resistance must be made good. The recent Approved Document P makes specific reference to the electrician's responsibility to ensure that the fire resistance of any floor, ceiling or wall that any services he has installed pass through, are properly re-instated, with possible legal consequences for non-compliance.

IEE Wiring Regulations 16th Edition BS 7671:2001, section 527-02-01 reinforces this same stance, and this applies to all buildings:
“Where a wiring system passes through elements of a building construction...the openings remaining...shall be sealed according to the degree of fire resistance required of the element concerned...”

Part E of the Building Regulations in England & Wales, Technical Handbook 5 of the Building (Scotland) Regulations and Technical Booklets G & G1 of the Building Regulations (Northern Ireland)
Requires that penetrations through walls, floors or ceilings for electrical installations should be made good in order to minimise the transmission of sound.

When a hole is cut into a fire rated ceiling to fit a spotlight, the fire stopping ability of the ceiling is impaired. In the event of a fire, flames could penetrate through the light fitting and spread to the floor above with the subsequent risk to life and property. The spotlight itself could also be a source of fire due to the high temperature of halogen lamps and the proximity to flammable material. We suggest the use of either fire rated spotlights or the use of firehoods.


Heights of switches and socket outlets

The Building Regulations require switches and socket outlets in dwellings to be installed so that all persons including those whose reach is limited can easily use them. A way of satisfying the requirement is to install switches and socket outlets in habitable rooms at a height of between 450mm and 1200mm from the finished floor level.

Unless the dwelling is for persons whose reach is limited the requirements would not apply to kitchens and garages but specifically only to rooms that visitors would normally use.

The guidance given in Approved Document M applies to new dwellings. Note that if a dwelling is rewired there is no requirement to provide the measures described above providing that upon completion the building is no worse in terms of the level of compliance than it was prior to being rewired.