Melbourne is famous for having four seasons in one day. It can be sunny at 2pm. It can be pouring rain by 2:15pm.
This variability exposes a major flaw in the standard Australian sliding window.
When the rain starts, you have to close a sliding window. If you don't, water tracks immediately over the sill. It runs onto your floorboards. This means that right when a summer storm hits, you are forced to seal up your house. You suffer in the heat.
There is a solution. It requires changing the way your windows open.
The Awning Window is the unsung hero of the Australian climate. By hinging at the top and pushing out from the bottom, it solves the ventilation problem that sliders cannot.
The physics of an awning window are simple. The sash is attached to the frame by a hinge at the top.
When you wind it out, the glass creates a physical canopy.
Rain hits the glass. It runs off the bottom edge. It falls well away from the opening. Unless the rain is blowing horizontally in a gale, you can leave an awning window open 10 to 20 centimetres during a downpour.
This allows fresh air to cycle through the house. The water stays out. In a humid summer storm, this airflow prevents the room from becoming stifling.
Awning windows generally perform better thermally than sliding windows.
A sliding window relies on brush seals. These are fuzzy nylon strips. They reduce friction so the window can move. These seals are imperfect. They allow air leakage.
An awning window uses compression seals.
When you wind the window closed, the mechanism pulls the sash tightly against the rubber gasket on the frame. It locks into place. This creates an airtight seal. It stops drafts and noise much more effectively than a sliding sash ever can.
Historically, builders put tiny awning windows in bathrooms. They put massive sliding windows in living rooms.
This was largely because old hardware couldn't handle the weight of large glass panels. You had to use those fiddly little chain winders. They rusted. They jammed.
Modern uPVC awning windows are different.
The frames are steel-reinforced. The hardware is heavy-duty. We can build large awning windows that serve as main features in a living room. They offer a clean, uninterrupted view. There is no vertical bar in the middle like a slider. They offer superior weather protection.
Awning windows also offer a subtle security advantage. The opening is at the bottom. It is often restricted by the chain length. It is difficult for an intruder to climb through compared to a wide-open slider.
They also offer excellent privacy. You can have the window open for airflow. The angle of the glass reflects the sky. This makes it harder for neighbours to see in.
Stop fighting the climate
Renovating is about solving problems. The problem in Victoria is not just the cold, or the heat. It is the unpredictability.
You need a window that works when it is sunny. You also need a window that works when the change hits and the rain starts sideways. Old-school slider windows forced you to choose between dry floors and fresh air. But an awning window lets you have both.
