In hot climates with negligible heating needs, the building should be orientated to maximise exposure to cool breezes. The construction should aim to exclude harsh sun all year round, by minimising window sizes and/ or providing large overhangs or other effective shading devices.
All other climate zones, as well as alpine zones, need to incorporate passive solar heating and cooling. The extent of heating and cooling requirements depends on the climate. To determine if you need mostly passive heating, passive cooling, or a combination of both, you can compare summer and winter energy bills, consult a designer or an architect, or check meteorological records on the Australian Bureau of Meteorology website.
In the southern hemisphere, living areas should be ideally orientated within the range of 15°W-20°E of true or ‘solar’ north (20°W-30°E of true north is considered acceptable). Accurate location and direction will enable standard overhangs to prevent overheating in summer and allow lower winter sun to heat the building with no extra costs or effort from the occupants. On the other hand, a poor orientation will result in heat loss in winter and will lead to overheating in summer, by allowing low angled west or east sunlight to strike glass surfaces. North facing walls and windows should be set back significantly from large obstructions to the north, like trees, fences and other buildings. Keep in mind that they cast shadows two to three times their height in mid-winter.
The distance to a single storey building to the north should be a minimum 5.5 metres, to a double storey at least 10 metres.
- If possible, garages, carports and other buildings or structures shouldn’t be placed on the northern side of the site.
- Consider sharing walls with neighbours, especially on the east or west boundary as it will minimise unwanted heat loss or gain through these walls.
If you do want to know more about optimal house sitting and how to arrange your floor plan for optimal solar access please check out our other articles.