At first glance, the basic function of a window is to afford a view from the inside to the outside, allow natural light in, and keep wind, rain, insects, dirt and even intruders out. Scratch that surface though and you’ll find we expect a whole lot more.
- Windows must be strong enough to withstand the driving force of a storm.
- They have to be able to resist the formation of condensation on the inside glass surface when the weather outside is cold.
- They have to provide a source of ventilation and allow fresh air into the building when desired.
- When ventilation is not required, they must close and seal tightly to prevent drafts and the discomfort of air leakage.
- Windows can be an important means of escape during an emergency.
- We also want our windows to act as a barrier to the transmission of noise from outside into the building.
- We expect our windows to allow us to take advantage of solar heat gains, while reducing heat loss due radiation, conduction, convection and air leakage in winter and reduce undesirable heat gain in the summer.
- Windows must be durable enough to last and perform satisfactorily for the lifetime of the building with a minimum amount of maintenance.
- All this and they must be affordable too.