The most cost-effective strategy to reduce your energy costs is to try not to use it in the first place.

Target the high-use areas first such as space heating/cooling, hot water, refrigeration and cooking. Lighting efficiency is cheap and easy to achieve and while the savings are relatively small they still contribute to the greater energy use picture.

Sound house design is paramount. Once the energy needs of a structure have been minimised there should be no need to invest heavily in a home heating system.