Frequently Asked Questions

Look for the National Fenestration Ratings Council (NFRC) label on the window or patio door. This label shows the U-value, Solar Heat Gain, and visible light transmittance values. Other places to look for information on energy efficiency in windows and patio doors are:

► U.S. EPA Energy Star Homes Program

► Efficient Windows Collaborative

Air infiltration refers to the movement of air through a window or patio door past weatherstrip or other possible openings. Look for windows designed for absolute minimum air infiltration. A value of 0.3 or less is desirable.

The rough opening is the opening in the wall framing where the window or patio door fits. Usually, the rough opening must be sized 1/2 inch larger than the frame in both width and height.

Clad refers to the covering on the exterior window or patio door unit. From the inside, you see the beauty of wood while the aluminum or vinyl clad “shell” on the outside ensures the life of your wood windows for many years and reduces the amount of necessary maintenance.

Seal failure occurs when the seal between the two individual panes of glass in a typical insulating glass unit is broken. You know a window has failed if there’s moisture in between the panes of glass. Contact us to determine if there is warranty coverage and to help identify what needs to be done to fix it.

Yes. The historic integrity of an older home can be maintained while improving energy efficiency by replacing the windows with new energy efficient windows of the same style as the original. Refer to our dealer locator for assistance in finding a supplier who can help answer your remodeling questions.

Low-E, or low-emissivity, refers to a transparent metallic coating applied to one surface of an insulating glass unit. A window with low-E glass can lower your energy bill because in the summer it reduces the amount of the sun’s heat from entering the home, lowering the cooling demand. In the winter, low-E reflects some of the interior heat back into the home, reducing the need for heating. Some types of low-E glass are designed primarily for summer cooling, and some are better for winter heating. Refer to our dealer locator to find a supplier who can answer your specific questions related to low-E.

Tinting reduces the amount of light into the home, provides a pleasing tone to the view, and can help keep the heat out.

Furniture and carpet fading occurs when the energy of ultraviolet (UV) radiation alters the chemical structure of dyes and other colorants. Low-E coatings can provide a reduction in UV transmittance. However, in addition to UV light, other causes for fading and color changes might include exposure to humidity, oxygen, visible light, and heat. While low-E coatings can greatly reduce fading, it is important to remember that various types of materials (wood, fabrics, paint, rugs, etc.) react at differing fading rates depending on the colorant type and its susceptibility to fading from any of these causes.

Window products are designed to perform in various applications and weather conditions/exposures. Manufacturers can certify the performance grade of their products through independent testing laboratories. These certification programs define window products by performance class (residential, light commercial, commercial, heavy commercial, and architectural) and performance grade (15, 20, 25, etc.). Local building codes likely define the minimum performance grade. When choosing a product for a specific structure, it is important for the buyer to take into account issues such as the building’s design and exact location. Structure location determines general weather exposure and protection. For instance, a structure on a bluff may need a higher performance grade than one protected by windbreaks. The size and height of a building are also a consideration. Architects and your local building code department are excellent resources to discuss performance classes and grades. We recommend you also discuss performance grades with your contractor.