A building's location and surroundings play a key role in regulating it's illumination, for example; designing northern hemisphere buildings with south facing windows increases the amount of sun (and heat energy) entering the building.
Correct placement of windows and skylights that reflect light can reduce the need for artificial lighting. Lighting accounts for 7 per cent of a typical household's energy bill (energy saving trust, 2013). Getting into the habit of switching things off when they're not in use is part of energy awareness. Simple initiatives such as changing to low energy light bulbs save money in the long run and they pay for the initial cost in energy terms in approximately two years. Careful lighting designs can incorporate choosing the minimum wattage and the lighting of a specific work area only in any room. Effective energy-efficient building design can include the use of low cost Passive Infra Reds (PIRs) to switch-off lighting when areas are unnoccupied such as toilets, corridors or even office areas out-of-hours. In addition, lux levels can be monitored using daylight sensors linked to the building's lighting scheme to switch on/off or dim the lighting to pre-defined levels to take into account the natural light and thus reduce consumption.