Energy

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

Lighting design

For maximum energy efficiency, homes should be designed to make the most of natural daylight.

Lighting accounts for 13% of electricity used in an average New Zealand home.

For maximum energy efficiency, homes should be designed to make the most of natural light during daylight hours.  See daylighting for details.

However, artificial lighting is necessary for times when natural lighting is not available/adequate and for specific tasks. Artificial lighting – especially using LED fixtures – can be designed to provide appropriate lighting levels while using energy efficiently.

A report commissioned by EECA calculated that LEDs can save householders $75 per lamp over their lifetime compared to using incandescent bulbs. The net savings to New Zealand from reduced peak electricity demand are even higher, at $150 per lamp.

EECA calculations show another benefit of LEDs – reduced greenhouse gas emissions. “If every New Zealand household installed LED lighting, we’d avoid 82,000 tonnes of greenhouse gas emissions every year – the emissions of almost 34,000 petrol cars.”

LEDs only made up 20% of the residential lighting stock in 2015, but that figure is changing fast. Around 4.6 million incandescent light bulbs were sold in the year May 2015–April 2016, but this halved to around 2.8 million in the year to the end of April 2019. Over the same period, LED sales grew from around 248,500 to over 604,000. (LED sales are lower than incandescent sales because LEDs last much longer.)

  

Updated: 06 October 2021