Intelligent design, orientation and fitting out of your home can save a lot of heating and cooling costs.
Here are some factors to consider when trying to achieve a high energy efficiency rating.
Which way will your home face?
Position the living areas of your home to the north to benefit from maximum sunshine and light during the day. Bedrooms are better placed on the south side for cooler sleeping at night. If you’re building in a sub-tropical or tropical zone and prefer to block the summer sun, face your home to the east and west.
Benefit from passive solar
The natural resource of the sun needs to be managed to heat and cool your home. Smart placement of windows, walls and floors will help collect, store and distribute the sun’s heat during winter and block it in summer. Eaves or shallow verandahs over the north-facing windows will protect the house from overhead sun during the summer, while letting in the low-angled rays in winter.
Windows can make a difference
Large windows are great for panoramic views, but can leak a lot of heat in cold weather and may need screening in summer. A range of different glazing surfaces are available, including Low-E glass. Double glazing offers much better insulation than single glazing. Winter performance of windows can be improved by using close-fitting curtains with pelmets. Reflective backings on the curtains will aid their heat-repelling ability in summer.
Insulate to stay warm
Energy savings depend on home insulation, which acts as a barrier to heat flow and will keep your home warmer in winter and cooler in summer. Insulation can be of two types. Reflective insulation that uses a silvery surface to resist the flow of radiant heat and works best in warmer climates, where reducing heat gain is the priority. Bulk insulation in the form of batts resists the transfer of conducted and convected heat and is good for cooler climates where saving heat is important. Insulation can be added to the roof, ceiling, walls and floor, including underneath suspended floors. Sealing up the gaps in a home will reduce the power bill. Installation of draught excluders and doorway seals to keep the heat in.
Adding thermal mass
Thermal mass is the ability of a material to absorb, store and transmit heat energy. Concrete slabs, particularly waffle pod slabs, have sufficiently high density to soak up heat from the sun during the day and release it slowly during the night. Well-designed and positioned windows in a home will facilitate this process of heat absorption and release, as will centrally positioned radiant heaters.
Consider dark coloured roofing
The benefit of a dark coloured roof in cooler climates is now being recognised. Tiles and steel roofs in Australia tend to be of medium to dark colours, measured by the amount of solar radiation absorbed. A dark roof could be beneficial in colder, heating-dominated climates like Victoria, Tasmania and parts of New South Wales. The reverse is true in warmer climates, such as Brisbane and further north, where a light-coloured roof will be a significant repeller of heat, even when roofing insulation is fitted.