Ballan House

The brief for the project was to design a resource efficient home on a modest budget; one which the clients would foresee living in on a long term basis. Low embodied energy in materials, low energy consumption in operation, and low water usage were the principal objectives of the brief. The choice of strawbale as a wall material provided a good solution to meet several of these objectives but instead of allowing the traditional use of this unconventional material to dictate the design, we wanted to use it in a modern way for a contemporary style house. Traditionally a favourite with owner builders and alternative life stylers, we wanted to expand the repertoire of this flexible material and use it within a contemporary style to show that strawbale building need not only be suitable for a small niche market, but can also serve the needs of modern lifestyles and address the ever increasing concerns of climate change.

Strawbale is a highly renewable material. It’s a waste product from the grain harvest, whose abundant quantity can be regrown annually. As well as being of low embodied energy, it is also highly insulative with a conservative Firstrate R-value of 5 for this completely natural product, although an actual R-value of 10 is more widely accepted. The combination of straw and a ‘breathable’ render help moderate the internal humidity inside the home and create a comfortable air quality.
For the non-habitable utility rooms of the house we have used Shadowclad plywood cladding which also contributes to the low eco-footprint ethos of the house. The raw material is from sustainably managed plantation and the manufacturing process minimizes waste and water usage. The timber cladding provides a thermal break between external temperatures and the highly insulated stud wall.
This combination of heavy and lightweight construction, all founded on a thermal mass concrete slab, form a hybrid building best able to passively cope with the extremes of temperature between day and night, and summer and winter that are experienced in the Moorabool Shire.

The house is fitted with water efficient tapware throughout and a low volume flush toilet. All rainwater from the roof is harvested into a large tank which is then fed back into the house. There is also a connection to the mains water supply but due to the owners diligent water saving practices, they have never needed to draw from the mains supply. All overflow from the tank runs into a smaller tank which can be used solely for garden use.

A solar hot water service provides year round hot water with only four months of the year requiring electric boosting. A one kilowatt grid-interactive photovoltaic system meets a majority of electricity requirements and has reduced net consumption down to as low as $8 worth for quarterly usage.