Correct orientation of your home and the site allows you to maximize sunshine when it is needed for warmth, and to exclude the sun’s heat when it is not needed.
The sun rises in the east and sets in the west. The sun is higher in the summer sky and lower in the winter sky, and predominantly in the northern sky. Correct orientation of your home and the site allows you to maximize sunshine when it is needed for warmth, and to exclude the sun’s heat when it is not needed.
Orientation of the main living areas towards the north most easily allows you to control the sun’s rays for heating internal spaces in winter and to exclude direct hot summer sun. A well designed house ideally should be elongated to open towards the north. As a result, there is less building exposed to the low angle hot morning and afternoon summer sun on the shorter eastern and western sides of the house. The high angle summer sun is also easier to control with appropriate eaves overhang along the northern side providing shade to the northern living areas in summer. The longer northern side of the house benefits from the low angle winter sun. Allowing this sun to penetrate below the eaves and into the living areas will warm these spaces in winter.
The building site can have a major effect on orientation. Good passive solar performance at minimal cost can be achieved if the site has the right characteristics. A site that can accommodate north facing daytime living areas and outdoor spaces is ideal.
Sites running north/south are ideal because they receive good access to the northern sun with minimum potential for overshadowing by neighbouring houses. Sites running east/west should be wide enough to accommodate a north facing outdoor space. Overshadowing by neighbouring houses is more likely to occur on these sites, especially if the neighbouring houses are two storeys.
Diagrams from yourhome.gov.au.
A north facing slope increases the potential for access to northern sun. A south facing slope increases the potential for overshadowing.
Views to the north are an advantage, as north is the best direction to locate windows in living areas. If the views are to the south it is best to avoid large areas of glass in order to minimise winter heat loss.
The ideal orientation for living areas is within the range 15° west to 20° east of north, although 20° west to 30° east of north is considered acceptable.
This allows standard eaves overhangs to admit winter sun and exclude summer sun at no additional cost to the build. Poor orientation can exclude winter sun, and cause overheating in summer by allowing low angle east or west sun to strike glass surfaces.