A Guide to Window SHGC and U-Value

Certain factors help experts determine a window’s energy performance and assist homeowners in making informed decisions. Such information is typically found on the label of windows, so you have to look closely or ask window sales representatives for those details. 

In this post, we discuss the essential window ratings you should know: solar heat gain coefficient (SHGC) and U-value.

SHGC

SHGC measures how much solar heat enters your home through the window glass. The higher the SHGC rating, the more solar energy enters your home through the window. This can be beneficial in cold climates because windows with high SHGC allow for effective passive solar heating, which keeps the home naturally warm without relying too heavily on the heating system. However, the best window options in hot and dry climates are those with a lower SHGC.

U-Value

The U-value measures the amount of heat that enters your home through the window. This appears to be similar to the SHGC, but there is one key difference – U-value rates non-solar heat. The lower the window’s U-value, the better it will insulate your home against outdoor heat. During the summer, the window helps to maintain a naturally cool and comfortable indoor environment by preventing excess heat from leaking into your home. As a result, you can avoid high energy costs.

Which Ratings Are Right for You?

There’s no one-size-fits-all solution when choosing replacement windows because you must consider your local climate, window orientation and personal preferences. Homes located in areas that experience both hot summers and cold winters benefit from windows with a low U-factor and SHGC. On the other hand, homes in predominantly cold climates should get windows with high SHGC to supplement their heating.

High-quality replacement windows can provide a wide range of benefits to you. That’s why you should be extra discerning when looking at your options. At V. Nanfito Roofing & Siding, we’ll help you find the windows that best suit your needs. To schedule a consultation, call (203) 639-1634, or fill out the convenient online form.