The energy-efficient home

The most effective way to save on energy bills is to consume less energy. As these guidelines will demonstrate, the sensible modern home builder considers climate and plans a house accordingly so that it is energy efficient.

Owners of existing houses can take simple steps to reduce energy bills. There was a time when taking account of the climate was a necessity.

• In warmer regions homesteads and farmhouses were positioned to take advantage of breezes, many incorporating a comfortable "breezeway" through the centre of the building.
• Verandahs shaded the interior from the hot summer sun.
• Country dwellings were often modest in size and rooms could be closed off during the cold months to reduce the loss of warmth from heated kitchens and living areas.
• Large stone or brick fireplaces provided a heat-absorbing and heat-releasing "thermal mass" to moderate interior temperatures, and made use of locally available wood as an energy source.
• Trees were planted nearby not merely for aesthetics but to serve as protection from wind and for shade.

In the 20th century, relatively cheap power derived from fossil fuels — mainly electricity generated from coal and oil — made it possible for buildings of any design to be effectively heated and cooled. Extravagant energy consumption continued for decades in industrialized countries until the embargo by oil-producing nations in 1973 made people realize that they could not take for granted the continued supply of cheap fuel. Energy conservation received a further boost in the 1980s with the recognition that emissions from burning fossil fuels are not only polluting air, water and land, but also contributing to a process of global atmospheric warming. When building a home, or looking to buy a house, it is important to consider energy efficiency. This will determine whether the house is comfortably cool in summer and warm in winter without using large amounts of energy and imposing high fuel costs.

For energy efficiency, the most important features to consider when planning or buying a home are the site, orientation and layout, the location and design of windows, and the construction materials. These factors contribute to a "passive solar energy system" in which the building is used to collect, store and transfer the sun's heat without the aid of any "active" or mechanical system. Energy demands in modern homes are such that use of solar energy alone may need to be augmented by conventionally powered heating and cooling systems.