energy efficient windows

A key measure for rating the energy efficiency of a product is its U value.

The higher the U value the more heat flows through a building component so a good value is a low one as you want to keep heat inside the building or outside depending on the time of year.

Living in a building that has low U values has a number of advantages:

1. It saves money on the energy bill
2. It helps preserve the environment
3. It is good for your health
4. It gives better indoor comfort