All ENERGY EFFICIENT qualifying windows also bear a label from the National Fenestration Rating Council (NFRC). NFRC provides unbiased energy performance ratings for windows (or "fenestration".) Independent NFRC ratings provide the basis for our window performance requirements.

NFRC's labels provide product-specific performance ratings for technical qualities such as U-Factor (the rate of heat loss from your home through the window during the winter), and Solar Heat Gain Coefficient (how much heat your house gains from the sun during the summer.) Just as an EPA sticker on a new car will give you a guideline to the car's fuel economy, the NFRC label on a window gives consistent ratings that can help consumers determine both Winter and Summer performance characteristics. Look for low U-factor ratings for highest efficiency performance. 

The National Fenestration Rating Council's (NFRC) Energy Performance label is designed to help consumers measure and compare the energy performance of different window brands.  Just as the EPA sticker on a new car will give you a guideline to the car's fuel economy, the NFRC label gives consistent bench-marked ratings that can help consumers compare performance characteristics of different window and door brands.

In the winter, the lower a window's overall U-Factor, the less heat you will lose through that window.  A lower U-factor means you'll use less energy to heat your home, saving you more since your furnace isn't running as much.  U-Factor ratings generally fall between .20 and 1.20.

In the summer, a lower SHGC means less solar radiation is admitted through your window. Your home will remain cooler and your air conditioner will not have to work as hard. SHGC is expressed as a number between 0 and 1.

Visible Transmittance (VT) measures how much light comes through a window.  The higher the visible light transmittance, the more light is transmitted through the window.  VT is expressed as a number between 0 and 1.

Condensation Resistance (CR) measures the ability of a window or door to resist the formation of condensation on the interior window or door surface.  The higher the rating, the better the product is at resisting condensation formation.  CR is expressed as a number between 0 and 100.

The lower the number, the less drafts and air infiltration into your home.  The lowest number the government assigns is a .1 and our Windows are better than the best industry standard.  Any windows with an air leakage number above .3 fail this test.

The U-Factor is a measure of the rate of heat loss through a window, the lower the “U-Factor”, the lower the amount of heat loss.  This is important in colder climates, where installing windows with lower “U-Factors” will reduce the percentage of heat that leaves your house.

The R-Value is the resistance that a window has to heat flow.  If a window has a high R-Value, it will lose less heat than a window with a lower R-Value.  Simply put, the R-Value is the inverse to the U-Factor.  However, when rating windows, the U factor is more important because it is indicative of the efficiency of the whole window not just the glass.

The Solar Heat Gain Coefficient measures the rate of heat gain through a window.  The lower the solar heat gain, the lower the amount of heat that will enter from the outside.  This is important in warmer climates, where air-conditioning is commonly used on a regular basis.