The possible tripling of energy costs within the next ten years has placed the heat on current housing design principles, building advisory service Archicentre warned this week.
An energy-wise home requires a complex mix of well-insulated, high thermal mass, intelligent glazing and ventilation, as well as optimal orientation and the inclusion of energy-saving appliances.
Archicentre South Australia's Edward Lukac said the recent statement by the head of Origin Energy, Grant King, that energy prices could triple in ten years means home owners currently paying $1,700 a year in energy costs will be paying $5,100 annually - or over $100 a week for energy.
"This will come on top of increasing water prices which are set to double as State Governments move to claw back the costs of costly desalination plants and other water infrastructure."
Mr Lukac said the skyrocketing costs of energy and water are making the initial investment in water saving and energy efficient design such as siting on the land, double-glazing and water tanks a far more attractive economic proposition for homebuyers.
"The cost saving starts with the design and siting of the home, including making provision for natural light in the main living areas and the orientation of the home to gain the maximum benefit for solar heating and provision for water harvesting", he added.
Archicentre advises that anyone considering building their home should first sit down with their architect and consider the home's design and energy components to ensure they end up with the home they want.
The first step in orientation is maximising the northern aspect, where exposure to the sun is best controlled. Eaves and pergolas can be designed to block the summer sun, yet still allow winter sunshine to penetrate.
North-side deciduous trees that shade the house during summer allow prime access to the sun once they have lost their leaves in winter.
It is important to prioritise rooms based on access to views and solar penetration. An open-plan kitchen and living area, for example, should have top position, while bedrooms or bathrooms require less daylight, as they are largely used for short periods of time, or at night.
Zoning the home means that unused areas can be closed off, and cooling and heating appliances can be designed for maximum efficiency and minimum use.
Insulation is paramount to the energy-wise home experience. Lining the roof, walls and floor can reduce heat loss in winter and heat-gain in summer. Consult an architect about the requirements for effective home insulation.
Materials with a high thermal mass, like stone, brick or rammed earth, take a long time to heat up and a long time to cool down. A concrete slab, with its high thermal mass, can reap huge benefits from prolonged exposure to the winter sun, radiating warmth at night, when it's needed most. Walls with a high thermal mass should be shaded to minimize a heat load in summer.
Glass is a very poor insulator. In an energy-efficient design think about size, location, glazing type and window coverings. Other important factors include:
- locating windows away from the western sun, and in some areas, the eastern sun
- placing tight fitting pelmets over curtains and blinds to trap air and create a layer of insulation to reduce heat loss on winter nights,
- reducing heat load and glare with specialised glass treatments.
Archicentre is running a series of free seminars on buying, building and renovating. Details can be found on their website.