This house is on approximately 100 acres of mostly cleared undulating pasture surrounded by the Karri forests of south west WA, with an existing dilapidated farm house and dis-used tobacco kilns which the owners have renovated for holiday accommodation and artists gallery / studio.
The owners brief was for a passive solar working farmhouse with rammed earth walls. They wanted to be owner builders. As this was to be a working farmhouse, the overall concept was of practical and informal simplicity. This approach also lent itself to rammed earth construction and owner building.
A simple rectangular form on an east/west axis with a recessed courtyard became the starting point and basis of the design. As this is a passive solar home careful consideration was given to the area of glazing in relation to wall area to all elevations.
In winter the sun’s rays are trapped by the glazing and penetrate deeply into the living areas, main bedroom, meals, bathroom and second bedroom to strike the tiled concrete floors and rammed earth walls which absorb this heat energy and slowly release it back into these spaces.
Other passive solar design considerations included high thermal mass in the form of rammed earth walls and tiled concrete floors, bulk insulation to the roof and ceilings and good cross-ventilation. In this region cooling in summer is not a problem and with adequate shading and plenty of thermal mass to absorb unwanted heat, plus good cross-ventilation, no auxiliary cooling system was required.
An important feature of the home is a large expanse of glass in the living area with high level double glazing facing north to allow deep penetration of the warming winter sun.
This high level window necessitated a vaulted ceiling to the northern end of the living area, which was continued into the kitchen area. This has created a sense of space to these areas and the large volume of air has a cooling effect in summer.
Another important feature of this solar home is the solar pergola over the north/east courtyard off the living area. The pergola allows low angle winter sun to penetrate into the building and provides shade from the high summer sun.
The materials chosen reflect the built environment in this area. Rammed earth walls sourced from the local area, Jarrah weatherboard cladding from a small local mill and a corrugated zincalume roof reflect the vernacular architecture of this sheep and cattle-farming district.