On the surface, the exterior doors, patio doors and skylights in our homes are judged on their basic functionality. Exterior doors are the means by which we enter and exit our homes. Patio doors provide the same enter/exit function in addition to allowing the natural light and warmth of the sun to fill our living spaces and give us an expanded view of the great outdoors. And skylights open the roofs over our heads to the light and warmth of the sun and, in some cases, open for cooling ventilation during summer months. Beyond these obvious duties, we expect them to do a whole lot more.
- They must be strong enough to withstand the driving force of a storm.
- They must withstand efforts at forced entry.
- They have to be able to resist the formation of condensation on inside glass surfaces when the weather outside is cold.
- They have to open as a source of cooling ventilation, but when ventilation is not required, they must close and seal tightly to prevent drafts and the discomfort of air leakage.
- Exterior doors and patio doors are an important means of escape during an emergency.
- We expect them to act as a barrier to the transmission of noise from outside into the building.
- We expect to be able to take advantage of solar heat gains while reducing heat loss in winter, and then reduce undesirable heat gain in the summer.
- They must be durable enough to last and perform with a minimum amount of maintenance.
- All this and they must be affordable too.