Awning Windows
An awning window has a sash that pivots such that the bottom of the sash projects out when the window is opened. Because it consists of a single sash an awning window lets in more light light and ventilation than a multiple sash window such as a double hung or slider. The amount of air coming in through the window is adjusted by the angle the sash is opened. This design choice will allow the complete window area to be open.
An awning window may often be left open in a gentle rain where there is no horizontal pressure driving water through the sash opening The awning design means that the window sash itself can be used as a canopy to deflect the rain.
In cold weather, drafts are also better prevented with the awning style window as it depends upon a compression gasket to seal against air and water infiltration. The greater the positive (wind) pressure on the sash, the tighter it seals against the frame.
Security is good these windows as they usually have double locks. Screens are mounted on the inside of the frame and stay relatively clean. Washing these windows usually requires access to outside.