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The right windows add essential pops of personality to any home. Image Via: Donald A. Gardner Architects

The right windows add essential pops of personality to any home. Image Via: Donald A. Gardner Architects

Let’s be honest, when in the market for new windows, odds are the bulk of your focus is on finding the perfect balance between aesthetics and price point. Many of us barely sneak a glance at the window rating label, if at all. In fact, it’s not uncommon to hardly acknowledge that such a label even exists, at least until you realize how much money your currant windows could be costing you.

Energy Star estimates that each energy-efficient window will save an average of $30 – $120 per year. If you’re going to invest in your windows – whether you’re buying new or fixing existing models – why not make sure that you’re getting the biggest bang for your buck.

We’ll teach you how to properly read your windows’ rating label, how to identify the effectiveness of the brand used in your home, and how to improve a not-so-optimal rating. Whether you’re a new homeowner or you’ve lived in the same house for years, you’ll want to keep this article as a reference for years to come.

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Make sure a poor window rating isn't costing you money. MAC Custom Homes

Make sure a poor window rating isn’t costing you money. Image Via: MAC Custom Homes

The U-Factor:

What The Rating Covers: The U-factor measures the amount of heat that can be lost from inside your home. A good U-factor is especially important during the colder, winter months when you want to do everything you can to keep heat inside of your home while in order to keep you heating bills low.

What Rating To Look For: Where the U-factor is concerned, the lower your number is, the better. Good ratings typically fall in a range between 0.20 and 1.20, where the number is reflected in either standard or metric units, depending on the country of origin.

How To Improve Your Rating: Insulating your windows is the most effective way to keep your heat – and money towards your heating bill – from flying out the window during winter. Buy strips of rubber weather sealing from your local hardware store and use it to fill in any gaps between your windows and the framing. However, in a pinch, hanging some layered curtains can also help.

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Insulate your windows to help keep heat inside during winter. Image Via: Crisp Architects

Solar Heat Gain Coefficient:

What The Rating Covers: In contrast to the U-factor, solar heat gain measures the amount of heat the gets absorbed into your house through your windows. You’ll want to pay attention to this number in the summers when it’s important to keep cool air from fans or home conditioning units from escaping.

What Rating To Look For: Again, in this situation, a lower number is considered positive. The rating is expressed as a number that falls somewhere between 0 and 1. It expresses how easily heat is able to penetrate the windows.

How To Improve Your Rating: In a situation where you have a high solar heat gain coefficient, window film could be your best bet. It’s essentially a sheet of darkened shrink wrap that is applied to the inside of windows to help reflect the heat. This same technology is also frequently seen on car windows.

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Check how much light your windows reflect to stay cool during the summer months. Image Via: River Architects

Visible Transmittance:

What The Rating Covers: Visible Transmittance refers to the amount of natural light that is able to enter your home through the windows. While natural light may often be viewed as a matter of personal preference, since high amounts have been linked to mood enhancement and a cleaner aesthetic look, a good rating should be a strong consideration when buying.

What Rating To Look For: Obviously, a higher number is considered preferable. The rating will fall on a scale between 0 and 1 and reflects the amount of daylight that you will filter into your rooms. 

How To Improve Your Rating: When considering VT rating, you’ll want to minimize the amount of shading that is present on your glass, as clear windows reflect the most light. Other external factors such as the window’s positioning on your home’s exterior and the heaviness of the shades used, if any, should also be taken into consideration.

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Whenever possible, let tons of natural light in through your windows. Image Via: LDa Architecture & Interiors

Whenever possible, let tons of natural light in through your windows. Image Via: LDa Architecture & Interiors

Air Leakage:

What The Rating Covers: Air leakage is exactly how it sounds. This window rating component refers to the amount of wind that is able to penetrate your home through your windows during poor weather.

What Rating To Look For: These ratings typically fall somewhere in a range of 0.1 to 0.3. A lower rating is desirable over a higher one. However, it is important to note that, unlike the other window rating categories, a measurement for air leakage is optional. Some window brands may not display this number, but doing so is often a sign of superior quality.

How To Improve Your Rating: To improve air leakage, you need to focus on finding and mending the gaps between your window and it’s frame. Finding the leaks should be relatively easy, since it is often just a case of noticing a cold draft. After that, the Department of Energy recommends using a foam sealant to help fill in larger gaps also while taking additional measures such as staying on top of roof and chimney maintenance and making sure to cover unused exhaust fans.

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French doors and larger windows are inherently more susceptible to air leaks so be sure to check their seals often. Image Via: Dewson Construction Company

French doors and larger windows are inherently more susceptible to air leaks so be sure to check their seals often. Image Via: Dewson Construction Company

Window rating labels don’t usually inspire an excitable response among the average consumer. At least until it’s made clear how much money a window with a poor rating truly costs. Don’t let you’re money fly out the window. Instead, use this article as a resource to help you properly read a rating level, make informed decisions when purchasing, and fix up less-than-stellar models. In fact, you may want to keep this post for a later date. You never know when you’ll find yourself in the window market once again.

Do you pay attention to your window rating? Are you planning on taking any steps to help protect your windows from heating/cooling loss? Share your opinions with us in the comments.