Many indicators are used in the industry to rate the ability of windows and doors to be energy efficient and conductors of heat. Ideally, you’d want windows that are able to keep that heat in during cold winter months, and out during warm summers.

One useful index is the U-Value, defined by industry experts as the ratio that determines exactly how much heat is effectively lost through a given thickness of material. For the mathematicians out there, we might add that it is obtained by dividing the difference in temperatures inside and outside of a material by the rate of heat exchange. This given ratio will generally extend anywhere from 0.25 to 1.25. And since U-Values measure out how much heat is lost, the lower the value is, the better!

To compensate the need for efficient and aesthetically good-looking products, Bonneville has developed time after time new products that consistently beat the industry average in terms of U-Value

This is the case with our double-hung windows that currently register a U-Value of 0.30 for the KP LOW-E 180 model and 0.25 for the KP LOW-E 180/Ēvolv model, all while the industry average stands by at 0.31.

Actually, a big part of the reason that we’re able to get such great U-Values is thanks to our ēvolv glass technology, an added coating that redirects heat back into your home, all while also offering better light transmittance and less reflectance.

So when choosing your next window and door company, it is important to look at the U-Value. These matters especially if you’re looking into saving some energy (and some extra cash!) during the cold winter months and the hot summers ahead.