According to leading Australian roofing supplier, Bristile Roofing
, climatic conditions, building materials and orientation of a property are key considerations when designing, constructing or buying a house to take full advantage of energy efficiencies.
Passive Solar Design comprises of a selection of design principles for residential builders and home owners to maximise the benefits of the local environment, helping to keep houses cool in summer and warm in winter with the resultant low energy usage. These design principles have been tailored to a set of common Australian climatic conditions.
For instance, buildings in climate zones with hot dry summers and mild winters experience higher cooling loads, which can be reduced by using materials that reflect thermal heat such as roof tiles. Concrete roof tiles have been able to achieve 7.8% greater reflectivity than metal roofing in tests conducted in the USA.
Roof materials can be used to reflect heat away from the home and minimise the need for artificial cooling by releasing heat build-up within the home. Roof materials such as roof tiles also absorb heat slowly during the day in summer, store it and then gradually release it at night.
An effective roofing system should combine insulation, ventilation and roof sarking using high quality materials that are strong and moisture-proof. Soffits and ventilation can also assist in minimising energy use by maximising the release of heat build-up in roof space.
In winter, insulation can be utilised to reduce heating requirements by helping to prevent the escape of natural heat in internal living areas through the roof cavity. Insulation also plays an essential role in mitigating the transfer of heat in summer.
Orientation of the house and the strategic use of eaves can play a significant role in reducing energy use by blocking the higher angled summer sun and facilitating the entry of low angled winter sun to warm living areas. Eaves on the east and west should shelter walls and windows from sunlight, thereby minimising heat transfer into the home.
Commenting on home design and the impact of building materials on energy efficiency and comfort, Mr Michael Monro - Marketing and Sales Coordinator at Bristile Roofing says that each home needs to be designed taking into account the unique set of environmental forces that influence it. Simple design principles combined with complete understanding of the local climate will minimise the requirement for artificial heating and cooling in any household, thereby reducing environmental impact and the financial costs of everyday living.