Our organisations look for the following factors when choosing windows for our projects:

  • A low U-factor. This measures the rate of heat loss by the window. A lower U-factor does a better job of keeping heat inside when it's cold outside.

  • Double-pane windows. Energy-efficient windows typically have two panes of glass separated by an air gap. This slows heat transfer between indoors and out. They also reduce sound transmission, making for a quieter home.

  • Multi-glazed. The glazing process can protect a home from excessive UV rays.

  • Wood, vinyl or fiberglass frames. Wood is very energy efficient, but requires regular painting to prevent moisture damage. Vinyl is less expensive than wood and require little maintenance. Fiberglass and vinyl are fairly similar in their attributes, but fiberglass is more expensive.

  • Stay away from aluminum frames, which are less energy efficient they transfer heat very easily. One good option, however, is aluminum clad wood frames.