If you’ve looked at the results of any heat load calculation, you’ll notice that most of the heat from your home is lost through the windows.
To get around that, it’s common to install double glazed windows in modern homes. But these are often supplied with aluminium frames, which are very poor insulators so the heat leaks out through your door and window frames.
To avoid that problem, you can install thermally broken frames. These look the same as aluminium frames, but the inside and outside sections of the frame are held together with insulating connectors, so there’s no conducting path for heat to get from inside to outside.
Another option is composite frames. These have an aluminium layer on the outside, but timber on the inside. These combine the insulating properties of a timber frame, but they’re protected on the outside by the harder-wearing aluminium.
Alternatively, you can go for timber frames. These are a little higher maintenance, as the timber decays over time if not properly painted or varnished. But they are much better insulating than aluminium frames.
Lastly, there are uPVC frames. These are a plastic frame designed to resist UV degradation. They’re very common in Europe as they’re hard wearing and very good insulators. These are probably the best choice if you want to reduce the heating load of your home, but they’re more expensive than aluminium frames to install.
Aluminium frames will no doubt remain popular not just because they’re the most cost effective option, but also because they’re reliably low maintenance and they look good.
However as the cost of energy rises, many governments have started to introduce restrictions on uninsulated door and window frames, so while aluminium frames might still be popular in Australia now, it’s likely that we’ll start seeing more and more insulated frames appearing on new homes.