The frame material chosen for a window can be as important as the glazing itself.

Frames are available in a variety of materials - wood, metal (aluminum), fibreglass and vinyl (PVC), as well as combinations of materials - metal-cladwood, vinyl clad wood, etc. Each material has benefits and drawbacks in terms of insulating value, durability, cost, aesthetics and maintenance requirements.

Generally, a well-designed frame provides the best insulating value, though some materials inherently perform better than others. Due to their high level of conductivity, frames made completely of metal must have a proper thermal break in order to slow the flow of heat to the outdoors.

Because a window's potential solar gain is reduced by frame bulk - a frame can occupy up to 30 percent of a window's area - narrower frames with higher insulation valures are desirable. In Canada, the ideal residential combination is a window with high solar-heat gain and a narrow frame profile that minimizes blocking of the sun.

Modern multi-point hardware makes possible 25% more light, cuts wood use in half and is more secure than bulky old-fashioned frames.

An efficient window or door frame is one that maximizes natural light, view and solar gain if desired, by using a frame that is no bulkier than necessary.