When choosing new windows, it’s important to consider their energy efficiency. Choosing windows that will not transfer heat from your home to the outside air will save you money when heating your home during the winter. U-factor is a measurement of the thermal transmission of the glass in a window. It states how much heat is transferred from the warm side of the glass to the cooler side. A lower U-factor means a window transfers less heat. The U-factor rating takes into account any glazing or special construction meant to further insulate the glass against transferring heat. In cold or mixed climates, windows with a U-factor of 0.32 or less are most efficient. In a warm climate, a U-factor of 0.60 or less is sufficient. If you have questions about choosing a window with the best U-factor for your home and climate, your replacement window expert can help you make the right determination. Wallside Windows is not only a window installer, we’re the factory too! We proudly provide custom-fabricated replacement windows installed by experienced professionals. Call (313) 908-5243 or click on our website to find out how you can get a free home estimate today.