Passive Design Features
Solar Orientation
Finding the right fit for your family and your block of land is the big challenge facing all new home buyers. The right fit for your block of land isn’t just about how wide your frontage is or how many square metres the council’s floor space ratio will let you have; its also about assessing the solar orientation of your site, and finding a design that takes advantage of it.
The first thing to establish is where north is in relation to your block of land. “North-facing” is housing jargon that is sometimes thrown around without much thought for what it actually means. In the summer, when cooling a house is the most difficult, between when the sun rises in the east and sets in the west, it travels in an almost straight line, and only slightly veering to the north.
This means that east-facing windows are very exposed to heat from the sun in the morning, and west-facing windows are subject to the punishing afternoon sun. Lots of windows facing either of these directions are very likely to make your house hotter.
It is much harder for the sun to enter north-facing windows, and much easier to shield these windows from excessive exposure. The other great advantage of north-facing windows is that they let the much lower winter sun in, helping you heat your home when needed.
South-facing windows are unlikely to make your home much hotter, but they will make your home cooler in winter, when they will let almost no sunlight in but give heat lots of opportunity to escape.
This is why you should find or modify a design so that most living areas, windows and sliding doors face the north. The other elevations can have the bedrooms, bathrooms, laundries and garages and their smaller, less important windows.
The second thing you should think about is whether there’s a regular natural breeze that you can use to cool the house. For example, if you get a great southerly in the late afternoon, think about positioning bedroom windows in its path so they can be cooled down before bedtime
Remember: Most new home designs can be mirror reversed for no charge. Your driveway can be moved. You cannot, however, alter the path of the sun, or the direction of a breeze. At least, not without really big machines.
