Following my visit to the inspiring solar passive home at Naripinda, I was wondering how the rest of us could achieve a better environmental footprint for our houses. Many of us are stuck with older houses, and even new homes in Australia are still being built with little attention to their environmental footprint. Given sky-rocketing energy prices, concern for the environment is increasingly underpinned by a strong financial incentive to cut energy use.
The easiest way to achieve an energy efficient house is to incorporate all significant features right from the start, such as solar orientation, insulation in walls, ceilings and floors, thermal mass and double-glazed windows. The savings in running costs for energy efficient houses will very quickly pay back the initial outlay in extra spending, as an average of 39 percent of energy consumed in typical Australian homes is used for space heating and cooling.
Unfortunately, most existing buildings are nowhere near that ideal, and many homes leak energy at an alarming rate through lack of insulation, cracks in the walls or gaps around windows or door frames. Insulation should be a number one priority for all home owners, particularly in the cooler parts of the country.
In addition, some simple changes can keep energy bills and greenhouse gas emissions down. Changing all incandescent light bulbs for compact fluorescent lights immediately cuts household energy consumption by around ten per cent. Turning lights off when leaving a room further reduces energy consumption.
Contrary to widely held views, halogen downlights do not save energy. According to Sustainability Victoria, “Halogens are considered an energy intensive lighting option because several halogen lights are needed in the place of one fluorescent light bulb to achieve even lighting levels in a room. Most halogen globes used as downlights consume 50 watts each and an additional 15 watts for the transformer. A 50W halogen downlight used 3 hours a day will cost around $10 a year to run. If you had a room with 8 halogens and ran them for 8 hours each day, it would cost you over $200 every year!”
Another way to immediately reduce your carbon footprint is to turn appliances off at the wall when not in use. The Global Warming Cool It! website lists some surprising facts on standby power. For example, did you know that over one year, some microwave ovens generate more greenhouse gas running the digital clock than cooking food? Or that large-screen televisions, when used 6 hours a day, generate around half a tonne of CO2 emissions each year — more than a family fridge? In an average Australian home, items on standby power together generate over 750 kilograms of unnecessary greenhouse gas emissions each year.
In my own house, we were able to reduce our overall energy use by over 30 per cent simply through changing our light bulbs and modifying our behaviour. The savings were more than enough to pay for 100 per cent Green Power and thus reduce our household greenhouse gas emissions to zero.
For more information you can download the Australian energy efficient building guide.