The intense summer heat can make it hot inside the house if your windows are exposed to the sun. Good building design is the number one way to avoid sun exposed windows in summer, but if you are still left with the sun hitting your glass then make sure your windows are properly shaded in summer. Without adequate window protection, every square metre of glass in your house receiving direct sunlight equates to a single-bar radiator’s worth of heat inside. The good news is that with a little strategically placed shading you can block up to 90 per cent of all heat coming through your windows and still enjoy the view.
Shade structures can range from awnings to eaves, shutters, shade sails or trees, however the system you choose will depend on the bushfire risk at your property, and is something to consider during the design stage with a bushfire planning expert. Shade-sails can potentially accumulate flammable debris and embers close to buildings and the Building for Bushfire Guide from the Tasmania Fire Service says they should be angled at 18°. The guide also notes that where an adjacent structure is made from – or contains – combustible material, it should be located at least six-metres from the main building or designed and built to withstand exposure to bushfire, which limits the use of many shade sails. Check individual shade products for fire resistance details.
The orientation of your windows will also be a factor in how much shade is required. The side of your house that you can do most with is the north, where the trick is to employ horizontal shade structures such as eaves and awnings. In summer these will act like a sun visor to exclude the high and hot summer sun. In winter, the sun, travelling low to the horizon, will still peek under your shade structures to allow in precious winter warmth.
The east and west sides of your house are a little more challenging to shade effectively. At sunrise (east) and sunset (west) the sun hangs low in the sky. That means in summer it’s going to get under your horizontal structures for an uncomfortably long period. The trick to shading morning and afternoon sun is fixed “vertical” structures such as trees or shrubs. Pergolas hung with deciduous vines provide a cool haven, not to mention a beautiful garden feature, although their use will be dependent on the bushfire risk at your site, and it would need to be built from non-combustible materials in high-BAL areas.
Keep in mind that adjustable shading, such as mechanical awnings, can give you maximum control over how much sun enters your home.
The Green Rebuild Toolkit post Bushfire Shutters as a Shade Solution discusses how bushfire shutters can be integrated into the design of your home for shading and insect protection as well, giving benefits to fire-resistant features beyond a bushfire event. While shutters are commonly fitted very close to the window, another option is to design them for a verandah or porch to make a versatile indoor/outdoor space, as shown in this house renovated by H+H Architects in WA, which also features in the Green Rebuild Toolkit article Keeping an eye on the BAL: How sites affect bushfire risk.