Through the (Energy Efficient) Looking Glass: What You Should Know

When it comes to home improvement and design, windows typically don’t get the attention they deserve. People spend days, weeks, and even months debating paint color but just hours (or less) considering window options. While we may be a little biased, this attitude seems bizarre to us at Jack’s Glass since choosing the right windows can save you money, increase the value of your home, and enhance other design elements.

So… why the lack of interest in windows? We think it’s because the world of windows, especially energy efficient windows, can be overwhelming and confusing. Trying to decipher the jargon and pick the best windows for your home can easily have you feeling out of place. In fact, when you talk to some professionals, it’s almost like they’re speaking another language!

Jack’s Glass is here to guide you through the (energy efficient) looking glass and help you make sense of energy efficient windows. We’re not promising that reading this article will make you feel about windows the way you do about three day weekends but we are confident this article will have you looking at windows in a whole new light.

What are energy efficient windows?
The best place to begin is well, at the beginning. So what are energy efficient windows? “Energy efficient” is not a brand name or one specific type of window. Energy efficient simply means not expending unnecessary energy to achieve a desired state. In the case of windows this means not wasting heat or air conditioning in order to reach a certain temperature. It may also mean not wasting electricity to achieve a desired level of light in a room.

Your existing windows may be able to be modified to help improve their energy efficiency. For example, you can add storm windows, caulking, and weatherstripping to reduce air leakage. You can also add window treatments (like curtains) to help reduce heat loss (in the winter) and heat gain (in the summer).

However, especially if your windows are old, to achieve the highest level of energy efficiency you’ll want to invest in new windows with an ENERGY STAR status.

ENERGY STAR is a voluntary program, set up through the U.S. government’s Environmental Protection Agency (EPA), in which products such as windows, doors, skylights, and appliances are evaluated and rated as energy efficient or not.

To qualify as an ENERGY STAR product, windows must meet set standards on two metrics:

U-factor – Describes how well a window conducts heat. In other words, it is a number that represents a window’s resistance to heat loss. The lower the number the better.

Solar Heat Gain Coefficient (SHGC) – A measure of how much heat is admitted through a window. Expressed as a number between 0 and 1, the lower the SHGC the less heat the window transmits.

So just pick any ENERGY STAR rated window?
No. The type of energy-efficient windows you need for your home will vary based on several things one of which is climate.

ENERGY STAR offers energy performance rating criteria by climate to help you get a general idea of what ratings would be appropriate for your home.

However, keep in mind, these climate ratings don’t take into account a home’s design or the orientation of the windows.

For example, if you were looking at south facing windows, according to, “To be effective, south-facing windows should have a solar heat gain coefficient (SHGC) of greater than 0.6 to maximize solar heat gain during the winter, a U-factor of 0.35 or less to reduce conductive heat transfer, and a high visible transmittance (VT) for good visible light transfer.”

Another factor to take into consideration is how your windows will open. Different types may be more energy efficient. For example, a window that opens “awning” style is hinged at the top and opens outward. This type is often more energy efficient than a sliding style window because the sash closes by pressing against the frame thereby reducing air leakage rates.

You’ll also want to evaluate the different types of window frame materials available to you. There are a slew of materials to choose from each with pros and cons. Your choices include:


Pros: Vinyl tends to be budget friendly yet still possesses energy efficient qualities. For example, tight construction can reduce air leakage.

Cons: Color options for vinyl are limited and many people think it has a “cheap” look.


Pros: Wood is great at insulating making it very energy efficient. In addition, it tends to be long lasting. One thing to note: Wood is not a great option for homes in highly humid or rainy climates due to the potential for rot.

Cons: Wood requires more upkeep than some other materials (such as vinyl).


Pros: Aluminum is strong making it a good choice for homes that may face adverse weather such as hurricanes. It is also a practical material choice for homes in rainy, humid areas.

Cons: This is not the most energy efficient material since metal transfers heat readily.

Wood Clad

Pros: Wood clad window frames offer a low maintenance exterior and an energy efficient interior (wood).

Cons: This material is not the best choice for windows that may have repeated or prolonged exposure to water.

In summary, when selecting your ENERGY STAR windows you have a lot to consider including:

  • Climate
  • Home Design
  • Window Orientation
  • Window Opening Style
  • Budget
  • Personal Style Preferences

Why go for ENERGY STAR windows?
It’s a lot to consider, and after looking at everything you may feel overwhelmed and want to just stick with the windows you have. However, there are some real benefits to getting more energy efficient windows and ENERGY STAR windows in particular.

ENERGY STAR windows can help you minimize your heating, cooling, and even lighting costs. In fact, many home owners find that they recoup the cost of the new windows in utility savings in just a few years.

Furthermore, ENERGY STAR windows may qualify you for a tax credit.

If you’re looking to increase the value of your home, windows should be on your list. Replacing your windows is a great selling point.

Give Back
ENERGY STAR windows help reduce your energy usage meaning you’re helping to protect the environment.

Why go with a professional installer, like Jack’s Glass?
As you can see from this article, there’s a lot to consider with energy efficient windows. You’ll want a seasoned professional, like Jack’s Glass, to walk you through the entire process. Jack’s Glass will treat you like an individual and consider your specific needs such as window orientation and budget to find the perfect solution for you… not someone like you.

In addition to the selection process, to ensure energy efficiency, you’re going to want your windows to be installed by a professional. This will make certain the job is done right and that you’re saving as much as possible.

Contact Jack’s Glass today to find out more about ENERGY STAR windows.

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Jack’s Glass provides repair and replacement for auto glass, custom solutions for shower and tub enclosures, and many other residential glass items. In addition, we do custom glass projects for businesses. We proudly serve Cincinnati and Northern Kentucky, with locations in Elsmere, Covington, Alexandria and Dry Ridge.

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Image credits:
Energy Star map and climate rating:
Window opening types: