Background
The clients required a permanent home/office on their small property, located one hour’s drive from Adelaide. A bend in the winter creek that divides the property, creates a billabong (a deep waterhole) bounded by a high rocky bank. A house was required that would allow appreciation of the site without spoiling its beauty, but at a budget comparable with a “prefabricated” dwelling or an “off the plan” developers design (approximately (A$220,000).
The Design
A narrow house form, spans over the creek. Glazing each side opens the house to views in both directions, giving the feeling of living amongst the trees.
Structure and Materials
Two steel trusses forming the primary structure, were fabricated off site and erected by two men and a crane in two days. They were anchored by four small concrete piers, poured each side of the creek. Spanning between the trusses is a concrete floor slab on steel decking with a layer of rigid insulation. The “box” walling and roofing is plantation pine.
Sustainability and Environment
• House Size ‐ A floor area of 110m2 has proved quite adequate for the couple‘s permanent home and office. An efficient plan is a simple and effective method of limiting the environmental “footprint” of the building.
• Thermal Comfort ‐ This house avoids any air conditioning by the following design techniques:
1. Winter Heating The long sides of the house face north and south. The low winter sun from the north heats the black insulated concrete floor, storing heat for reradiating at night. Insulation to the underside of the slab, wall and roof combined with double glazed curtained windows aid the retention of heat. A small wood combustion heater provides additional heat when required, fuelled from timber grown sustainably on the site.
2. Summer Cooling Pressed steel screens shade the north facing windows in summer. A combination of ceiling fans and openable windows allow for efficient and effective cooling from cross ventilation. By closing the house during hot summer days and opening it during the cool evenings, comfortable conditions can be maintained without air conditioning.
• Materials Where possible Materials were selected that were:
‐ produced locally in a sustainable manner
‐ recyclable or reusable
‐ easily installed with little machinery
‐ created little waste
• Steel and aluminium are used in recyclable sections, whilst satisfying the design requirements for bushfire prone areas. Secondary framing is plantation pine grown in the state. Roofing and wall cladding is recyclable sheet steel.
• Services
1. Water Roof water is collected for use within the house.
2. Waste Water Is pumped 100 metres from the creek to avoid pollution and dispersed underground following treatment.
3. Electricity Photovoltaic cells are located on the adjacent shed, to power the house, with excess power fed back into the grid.
4. Hot Water Solar hot water panels on the house roof provide hot water at minimal cost.
• Environmental Impact The design represents the classic “Touch the Earth Lightly” approach, both visually and environmentally.