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Installing energy efficient replacement windows in your home is important because this task not only helps you save money on your utility bills, it increases your comfort while in the home as well. You likely have heard of Energy Star, especially if you’ve bought new appliances, windows or doors in the last few decades.

The Environmental Protection Agency (EPA) established Energy Star back in 1992 as a way to rate energy-efficient appliances and products and reward homeowners who decided to use them. By increasing your energy efficiency in your home, you’re doing your part to conserve the environment, while at the same time saving money on your monthly energy bills.

So what qualifies windows as being Energy Star certified? They must:

  1. Be made by an Energy Star partner
  2. Be Independently tested, verified and certified by the NFRC, or National Fenestration Rating Council.
  3. Include NFRC ratings that meet stringent energy efficiency guidelines developed by the EPA.

Performance criteria for windows vary by climate zone, so before buying windows for your Houston home, ask your trusted window installer about that. You can also look online for a map of the four different regions of the U.S.

A Look at Energy Star’s Rating System

Energy Star scores are rated on a scale of 1-100. Just like a grade you would get in school, the higher your energy score…the better. The score will evaluate energy performance based on billed energy usage. This is why Energy Star ratings usually refer to the efficiency of an entire building. For specific numbers on windows, for instance, you should look at the window’s NFRC label.

In a nutshell, while the ENERGY STAR label advises whether a product is energy efficient, the NFRC label helps people compare between energy-efficient products (in this case windows) by breaking down its energy performance.

A Bit About NFRC

The NFRC label helps home and business owners compare the various properties of energy-efficient windows, doors, and skylights by providing energy performance ratings in several categories.

When evaluating an NFRC label for your new windows, you will see these four categories:

  • U-Factor: Measures the ability of the window to prevent heat from escaping from the interior. You want a lower number, because that means it’s better at keeping the heat inside.
  • Air Leakage: This is a measurement of how much air will get into a specific room via the window. Again, you want a low number, which means you’ll have fewer drafts.
  • Solar Heat Gain Coefficient: This is a measurement of how well the window will be able to prevent unwanted heat gain – something that’s very important especially during the summer when you’re running your AC constantly. Once more, you want a low number, which will translate to less money you will have to shell out for cooling.
  • Visible Transmittance: This is a measurement of how well the window can effectively flood the home with daylight. On this one, a higher number is best because it means more natural light is allowed inside.


In general, you can save between $100 and $600 a year when you replace a single-pane window; you can save $30 to $200 a year when replacing double-pane windows.

Benefits of Energy Star Windows

By installing Energy Star windows in your Houston home, you can:

  • Save money
  • Use less energy
  • Reduce greenhouse gas emissions
  • Be more comfortable in your own home
  • Protect your valuables (low-emissivity coatings on Energy Star windows will reduce the chance of UV damage to flooring, furniture and carpets)
  • Give you assurances of certified, verified performance

Contact Amazing Exteriors

For more help deciphering Energy Star ratings on your new windows, contact us today at 512-428-8417. We can help you decide which kind is right for you.

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