Designing homes to conserve energy and use it efficiently, from sources that cause least environmental harm.

Switches, sensors, dimmers and timers

Switches, sensors, dimmers and timers can all improve energy efficiency.

On this page:

  • Switches
  • Sensors
  • Dimmers
  • Timers
  • Smart lighting

Higher cost options include fully programmable or automatic house lighting systems that will operate light and security systems to maximise operating efficiency.


For general space lighting, locate switches at room entry and exit points. Specify two- or three-way circuits where a space has multiple entry points and for stairs – this will reduce energy use and improve convenience by making it easier for people to turn on lights as they come in to the room and turn off lights as they leave.

For task lighting and accent lighting, locate the switches adjacent to the task area. That way, occupants won’t be tempted to turn on task lights when they’re not needed. An alternative is to locate task and accent lighting on a single control panel remote from the general lighting switch.

Each lighting installation should have its own control. A single switch point to turn on all lights in a room will waste energy.


Movement sensors turn lights on automatically when someone comes in to a space and turns lights off (either by movement or after a set period of time) when the person leaves. This can reduce energy wastage. Movement sensors use a small amount of power by being on standby, but this is much less than lights that are left on continuously.

Daylight sensors turn lights on when the room or outdoor area is not daylit.

For efficiency and convenience, specify movement sensors that:

  • incorporate a daylight sensor and/or timer so lights don’t turn on unnecessarily
  • have a manual over-ride function.


Dimmers can save energy and increase bulb life by reducing light output. Specify a dimmer linked to a photoelectric light meter to reduce artificial lighting when more natural lighting is available.


Delay timers can be specified to switch lights off automatically after a short period. This saves energy by ensuring that lights aren’t left on indefinitely, but can also cause safety issues if the light goes off without warning. Timers are more suited to spaces that are only used for short periods of time, such as toilets or store rooms. Schedule or programmable timers can also be used to turn lights on and off at particular times of the day or week. Specify models that have a manual over-ride.

Smart lighting

Smart lighting is a key element of smart homes, where appliances or systems can be controlled remotely by a smartphone or computer. Just a few features that are currently available include:

  • lights that turn on as your smartphone comes within range of your home at night
  • setting “holiday routines” that turn lights on and off at random intervals, making it look as if someone is at home when you are actually away on holiday
  • voice control of your lights (in conjunction with a separate controller). For example, you can ask for the living room lights to be dimmed, the security lights outside to be switched on or off or ask for your bedroom light to be switched off after you get into bed.


More information


Updated: 12 June 2023