Lighting accounts for 11% of energy used in an average New Zealand home, and that percentage is projected to increase in coming years. For maximum energy efficiency, homes should be designed to make the most of natural light during daylight hours. However, artificial lighting is also necessary for times when natural lighting is not available/adequate and for specific tasks.

Options to reduce energy usage

Options to reduce energy usage include:

• energy-efficient lamps
• two- or three-way switching for rooms with multiple exits
• sensors including:
  • movement sensors to turn lights on and off automatically
  • daylight sensors and/or timers to prevent exterior and corridor lights turning on unnecessarily – however, they continuously use about 5–10 W and should have a manual over-ride
• timers including:
  • scheduled timers with manual over-ride that switch lights on and off at particular times of the day or week – these are often used to turn lights on in the evening as darkness falls, and switch off during daylight and after people have gone to sleep
  • delay timers to switch lights off automatically after a short period of time – these can usually be adjusted to suit use patterns
• dimmers to reduce light output (and power consumption) for incandescent lights and fluorescent lights having electronic ballast – these can be linked with a photoelectric light meter to reduce artificial lighting when more natural lighting is available
• programmable/automatic lighting.