Environmental factors come into play when it comes to choosing the right replacement windows for Houston homes. The National Fenestration Council has a rating system that measures and compares the energy performance of windows. If you’re in the process of choosing replacement windows in Houston and you’re not sure what to ask your contractor, here are the numbers that you should look out for.

1. U-Factor

U-Factor indicates how fast a window assembly releases heat. The lower the U-Factor, the better the windows can help to insulate your home. Although the area’s climate is usually warm, replacement windows in Houston are still recommended to have a low U-Factor in the event of cold winters. U-Factor rating is from .20 to 1.20.

2. Solar Heat Gain Coefficient

Solar Heat Gain Coefficient determines the amount of heat from the sun that the window is able to block. The measurement is from 0 to 1. Lower SHGC means less solar heat entering through a window. This is a particularly useful rating to take note of for replacement windows in Houston as can get really hot during the summers.

3. Visible Transmittance

Visible Transmittance gauges the amount of light that enters through a window. To let more natural light into your house, opt for a window with a higher rating on a 0-1 scale. Higher visible transmittance for replacement windows in Houston can help you save more energy. Instead of leaving lights on, take advantage of natural light by having it brighten your home.

4. Air Leakage

Since heat loss and gain are affected by the cracks in the window installation, the Air Leakage rating measures the amount of air that goes through the assembly. You will want windows that have a rating of .3 or less. This is an important aspect for replacement windows in Houston when keeping your air conditioning on during the summers.

5. Condensation Resistance.

The rating for Condensation Resistance is from 1 to 100. The higher the number, the better the window is at resisting condensation from forming on its inside surface. Since Houston's climate can be both hot and humid, having replacement windows in Houston that can resist condensation is a must.

Choosing energy efficient replacement windows for Houston homes is important if you're planning on saving money. The National Fenestration Council's rating system doesn't just take into account the materials that you use, but also how the replacement windows are assembled. This is why a replacement windows project is better off left to a professional. You will want to make sure that your replacement windows are properly assembled. It will save you a lot of money in the long run.