When it comes to building design there are a lot of factors that affect livability and energy efficiency. In a hot, sunny climate like Australia’s, one of the most important factors to consider is orientation.
Orientation is the position of your home in relation to the path of the sun and the prevailing winds in your area. Orientation is important for harnessing the heating and cooling capacity of the natural elements across all seasons. It is also an essential component of passive design, ensuring that living and sleeping areas are optimally positioned to either take advantage of the sun and wind, or be protected from the elements.
If properly designed and implemented, correct orientation can make a home significantly more livable and energy-efficient, reducing reliance on heating and cooling systems and saving you money.
While there are principles for ideal orientation, often practical orientation may be limited by the size, shape or aspect of the block. However, with careful planning and design, good orientation can be achieved on almost any block.
Principles of good orientation
To achieve good orientation, the most important factors to consider are:
- Climate in your area
- True north and sun angles for your site or building
- Optimum building design for your climate zone
- Effects of climate change
In Australia, the path of the sun is to the north, so good orientation usually aims to have the living areas of the home facing north. North-facing rooms tend to receive the most direct sunlight during the winter months, while being easily shaded by eaves or verandahs in summer.
Maximising the northern exposure of walls and windows can help to light and warm the house during winter, while blocking as much sunlight as possible during the summer months.
Identify your climate zone
Depending on the climate in your area, you may need to focus on orienting your home for passive heating, passive cooling or both. For warm humid climates, like those of Queensland or Darwin, orientation is primarily about maximising shade and cooling breezes. For colder climates like Canberra or Hobart, orientation should focus on maximising direct sunlight in winter while providing shelter from cold winds.
Understanding the local weather patterns and climate are vital for ensuring that your home is properly oriented for your region.
Orientation for passive heating
Orientation for passive heating is about using the sun to heat your home in winter and keeping unwanted summer sun out. Orientation for passive heating aims to maximise northern exposure of walls and windows, while reducing east and west exposure to avoid overheating in summer.
Some principles for orienting for passive heating include:
- Build close to the south boundary of the site to protect solar access and maximise sunny, north-facing outdoor living areas
- Locate living areas on the north side of the home to take advantage of winter sun
- Locate openings to capture cooling summer breezes
- Ensure proper shading from summer sun
- Use smaller, well-shaded windows to increase cross-ventilation to the south, east and west
- If you do have poorly oriented windows ensure the glazing is well insulated with double glazing and thermally broken frames
- Avoid west-facing bedrooms to maintain sleeping comfort
- Plant deciduous vegetation on the north side to allow winter sun in but provide summer shade
- Landscape using fences and plantings to funnel cool breezes and block or filter harsh winds
Orientation for passive cooling
Orientation for passive cooling aims to minimise the effects of direct sunlight by using appropriate shading and maximising airflow and cooling breezes. This is especially important on the east and west sides of the house.
Some degree of passive cooling design is required in just about all Australian regions and climates. In hot humid climates that do not have cool winters, orientation should generally exclude direct sunlight and radiant heat (from nearby structures) at all times of the year while maximising access to cooling breezes.
Some principles for orienting for passive cooling include:
- Building design that favours narrow structures with long walls oriented to the breezes
- Room configurations that encourage natural airflow and ventilation
- Door and window placement to encourage natural airflow and ventilation
- Minimal east and west facing openings, with maximum shading
- Ample use of roof eaves and verandahs to provide shade from the sunlight
Wherever you live in Australia, it’s vital that you put some serious thought into home orientation to optimise the livability and energy efficiency of your home.