Rising energy costs and demands for higher standards for indoor climate comfort have forced designers to come up with new construction methods and materials for modern buildings. Still a lot of energy is lost at places where people enter these buildings. For a long time, it was thought that blowing a strong flow of air with an air curtain was sufficient to stop the hot outside air from entering the building but these curtains often make the situation worse.

Energy-efficient homes have significantly lower default and delinquency rates than typical homes, according to an internal analysis conducted for a major financial institution last year. Here's yet another reason why it makes no sense that Fannie Mae and Freddie Mac have effectively killed Property Assessed Clean Energy (PACE), a financing tool that has helped make efficiency improvements affordable for thousands of American homeowners.