Lighting
Maintain the lighting system to keep it operating efficiently
- (i.e. clean) light fittings to maintain light output - a dirty diffuser, shade or reflector can reduce light output by 20% (9)
- (i.e. clean) windows regularly to maintain the level of available daylight (4)
- replacement of discoloured diffusers (4)
- lighting equipment regularly and plan bulk lamp replacements (10)
good levels of daylight (while avoiding excessive heat gain, heat loss, or glare from glazing)
- lighting controls that take account of daylight availability (5 - section 9.5)
Specify/select energy efficient lamps and luminaires
- most efficient lamps (CFLs, T5/T8 fluorescent tubes, low pressure sodium, etc.) suitable for the application ()
- most efficient luminaires suitable for the application (5 - section 9.3)
- compact fluorescents lamps (CFLs) for tungsten bulbs (9)
- more efficient T8 (26mm diameter) fluorescent tubes for T12 (38mm diameter) tubes (9)
- external lamps [more efficient alternatives e.g. low pressure sodium lamps] (4)
- high frequency ballasts (4)
- mirror reflectors on twin tube fluorescents (4)
Adopt an efficient lighting controls strategy (and zoning) with effective central and occupant controls
- daylighting linking and PIR only in low occupancy areas (5 - table 9.11, 3 - Section 5.15)
- manual switching close to luminaires that are being controlled (5 - table 9.11, 3 - Section 5.15)
- clear labelling of all light switches, especially on multiway switch panels (7 - section 2.4)
- multiway switch panels of no more than 4 switches, to reduce tendency for all lights to be switched on regardless of need (7 - section 2.4)
- large lighting systems linked to BEMS to allow central control (e.g. out-of-hours sweep-down of all lighting) (5 - table 9.11)
- distinctively coloured ‘Green’ switches so that occupants can distinguish energy efficient from standard lighting (7 - section 2.4)
- flexibility to match lighting levels to varying occupancy levels in a zone e.g. half-lighting for cleaners or security staff outside core hours (5 - table 9.11)
- timeswitches and automatic controls to minimise and/or prevent out-of-hours lighting (4)
- passive infrared PIR absence detection lighting controls for intermittently used areas (4)
- time delay lighting control switches in store cupboards (4)
- automatic (e.g. time based and/or photocell daylight linked) lighting controls on exterior lighting (4)
- movement detection controls to exterior lighting (4)
- automatic (e.g. time based and/or occupancy sensing and/or photocell daylight linked) lighting controls on interior lighting (10)
- key tag operated lighting control switches in locked, intermittently used areas (4)
- more localised switching (10)
Avoid excessive heat gain, heat loss, or glare from glazing
- effective (user-adjustable & accessible) blinds or equivalent glare control (5 - section 9.1, 1 - section 1.5, 11 - Section 02/03/04)
Design for appropriate lighting levels and mix of task & background lighting
- good practice lighting (of task) levels in occupied spaces cf. benchmarks, e.g. BREEAM Offices: 350-400lux in general office area (5 - table 9.1, 2, 8)
- good practice installed lighting loads (including circuit load) cf. benchmarks and rules of thumb (5 - table 9.1, 6, 7 - section 2.4)
- survey of lighting levels around the building and comparison with task requirements (4)
- selective delamping where lower light levels are acceptable (especially in conjunction with provision of task lighting) (4)
Achieve good levels of daylight
- splayed reveals to improve daylight distribution, especially in deep plan spaces (5 - section 03/03/03)
- light internal surfaces (especially walls & ceilings) with high reflectance, avoiding dark surfaces which absorb useful daylight (5 - section 09/01/03)
- light wells or atria to bring daylight into deep plan buildings (11 - Section 1.2.2.3)
Support occupants to make effective use of lighting controls
- notices informing staff and occupants to turn off unnecessary lights (4)
- labelling of individual light switches (particularly on banks of switches) to enable better control of lighting by staff and occupants (4)
- notices informing staff and occupants about effective use of blinds to avoid "blinds down, lights on" when there is adequate daylight (4)
- staff and occupants (e.g. by posting notices) to avoid obstructing windows, which reduces available daylight (4)
- staff and occupants (e.g. in regular meetings or through training) to turn off unnecessary lights (4)
Reference Documents
| Series Number | Publisher | Title | |
|---|---|---|---|
| 1 | Society of Light and Lighting/CIBSE | Code for Lighting | |
| 2 | L 26 | HSE | Display screen equipment work - Guidance on regulations |
| 3 | Guide H | CIBSE | Building control systems |
| 4 | Carbon Trust | Focus - the manager's guide to reducing energy bills | |
| 5 | Guide F | CIBSE | Energy efficiency in buildings |
| 6 | LG | CIBSE | Lighting Guides (1, 2, 3, 4, 5, 6, 7) |
| 7 | TN 12/99 | BSRIA | Environmental Rules of Thumb |
| 8 | LG3 | CIBSE | Visual environment for display screen use |
| 9 | Carbon Trust | Energy efficiency in the work place - a guide for managers and staff | |
| 10 | BRE | The Office Toolkit - the guide for facilities and office managers for reducing costs and environmental impact | |
| 11 | LG10 | CIBSE | Daylighting and window design |