A group of students from the University of Wollongong took a typical Australian "fibro house," and retrofitted it with technology which includes solar panels, climate control, and an energy monitoring system. The end result, dubbed Illawarra Flame, is a net-zero home which offers a potential starting point for transforming many similar properties into low-energy dwellings.

For the uninitiated, the term fibro house refers colloquially both to homes built using asbestos-based construction boards, which are now banned for safety reasons, and the cellulose-based boards which succeeded them.

A fibro house is usually thought to be very energy-inefficient, and so its transformation into a modern net-zero house – that is, a home with no energy consumption nor carbon emissions annually – required more than simply bolting on some solar panels and calling it a day.

The third bedroom of the house was converted into an open-plan living and dining space, while existing bathroom and laundry rooms were supplanted by prefabricated pods which functioned similarly, but more efficiently. An additional pod was added to the exterior wall of both bedrooms to increase usable space, and the roof was fitted with above eye-level windows to increase natural lighting and ventilation.

Indeed, all the property's windows were replaced with newer, more energy-efficient windows, and modern insulation was added too. Recycled local hardwood from demolished houses was also used in the build.

Illawarra Flame's electricity is produced by a roof-based 9.4-KW solar panel system, which actually comprises two different panel types: a thin-film CIGS array is located on the north and south-facing sides of the roof to capture weaker sunlight, and a poly-crystalline PV array sits directly on top, for maximum efficiency in optimal sunlight.

The home's air-conditioning combines a Photovoltaic Thermal (PVT) air system, and a Phase Change Material (PCM) thermal store, in order to provide both cooling and heating, as required.

The PVT works by simply converting solar heat into thermal heat for warming the house. The PCM unit is a little more complex, as it captures the relative coolness from the outside air at night, to store it (typically in a material such as paraffin or salt hydrates), until daytime. This cold material is then released throughout the day to cool the incoming warm air.

Further energy-saving features include LED lighting, and a handy cutoff switch that allows power to essential appliances only. A Building Management System affords fine control over the assorted energy-saving systems, and enables residents to monitor energy usage.

Rainwater is harvested from the roof and stored in a 2.4 cubic-meter (85 cubic-foot) rainwater tank, to be later used for irrigation and clothes washing use. A grey-water system, which filters used water through a reed bed and slow sand filter, complements this.

Finally, Illawarra Flame includes an interesting aquaponics system that grows both vegetables and edible fish species.

"The fish in the tank produce nitrogenous waste, which is periodically pumped into the crushed terracotta garden bed," explains the team. "The plants in the bed remove the nutrients, leaving high quality water which returns to the fish tank. This produces a large quantity of food relative to the system footprint, while using far less water than traditional garden beds."

Illawarra Flame took over a year to design and construct, and was entered into China's Solar Decathlon, which took place earlier this month. The house duly won first place, receiving 957.6 out of a maximum 1000 points and gaining the additional distinction of receiving the highest score awarded in any Solar Decathlon competition, ever.

Once it has been painstakingly disassembled and shipped back from China, the house will be permanently installed at UOW's Sustainable Buildings Research Center.

Source: Illawarra Flame