One Stop Home Improvement

Decoding Window Energy Ratings: Understanding U-Factor and SHGC

Decoding Window Energy Ratings: Understanding U-Factor and SHGC


We’ve all heard a product advertised as “energy efficient” or having a high ENERGY STAR® rating, but these broad terms can cover several ratings. Are you familiar with what the ratings mean or the differences between U-Factor and SHGC ratings? Most consumers aren’t familiar with the different window energy ratings, and for good reason – there’s a lot of information!


Keep reading as we decode window energy ratings so you can understand U-Factor and SHGC specifics to make an informed decision on a window that’s best for your home.


What is a Window Energy Rating?

Have you noticed the little ENERGY STAR® certified stickers on windows? What about displays or signage in a store near the windows, claiming they’re energy-efficient? It’s easy to see the advertising and think that replacing your windows with anything labeled as energy-efficient will save you tons of money. However, in reality, the ratings mean different things, and you’ll want to look for a specific rating to save on your energy bills.


The National Fenestration Rating Council (NFRC) is a non-profit organization that assigns energy performance ratings to windows, skylights, and doors. You can find their labels on most windows, skylights, and doors, giving energy performance ratings in various categories, including air leakage, solar heat gain coefficient, visible transmittance, and U-Factor.


NFRC differs from ENERGY STAR® ratings in a couple of different ways. When searching for an energy-efficient product, look for an ENERGY STAR® sticker to ensure it’s energy-efficient. NFRC labels take it a step further and give specific ratings in different energy efficiency categories, helping consumers to better understand how energy efficient a specific window, door, or skylight is.


What is a U-Factor Rating?

One of the categories you’ll find an NFRC rating for is the U-Factor. What exactly is a U-Factor rating? It measures the amount of heat that escapes from a room with that specific window, door, or skylight placed in it. Essentially, it’ll tell you how well a room can retain heat with that individual product. The ratings range from 0.20-1.20, and you’ll want to look for a lower number to determine the most energy-efficient U-Factor rating.


This rating is especially helpful if you have rooms that don’t get much sunlight since they can be colder if heat escapes through the windows. U-Factor ratings can help you find a window that retains more heat in a room to help prevent drafts.


What is a SHGC Rating?

SHGC, or solar heat gain coefficient, refers to the amount of solar radiation transmitted or absorbed that is released. Essentially, SHGC ratings determine the amount of solar heat transmitted, ultimately determining how well the window provides shade. Heat gain can lead to stifling rooms, especially during the spring and summer months here in Lynchburg


SHGC ratings range from 0-1 and you’ll want to look for a lower number. Lower numbers indicate that you’ll save on your cooling bills since the window provides better shade.


What Should I Look for as a Consumer?

As a consumer, we urge you to look for ENERGY STAR® certified labels and NFRC ratings to get the most energy-efficient window possible. Looking for both of these labels will help you determine if they’re the right fit for a specific room in your home. For example, you wouldn’t want to choose a window with a high SHGC rating if the room already gets a lot of natural sunlight.


Window replacement companies offer a variety of windows, some that are energy-efficient and some that are not. Pay attention to the energy labels provided on the windows to save on your heating and cooling bills.



One Stop Home Improvement Shop’s Replacement Windows are Energy-Efficient

One Stop Home Improvement Shop makes selecting an energy-efficient window easy. 

Our window frame selection at One Stop Home Improvement Shop is the best in Lynchburg, offering a variety of styles and materials to complement your home’s unique style while offering eco-friendly benefits. Our window replacement service is easy, starting with a free estimate.

We’ll assess your current windows, offer suggestions for window replacement, and give you a detailed estimate based on your needs. Finding the perfect window fit and material is easy when hiring One Stop Home Improvement Shop.


Our MountainView Windows offers superior energy efficiency, meeting and exceeding all ENERGY STAR® standards. With a multi-chambered frame design and premium glass packages and glass fills, there are plenty of options. Our Low-E windows and durable materials will protect your home while never harming our environment. We also have vinyl windows made from uPVC, a great eco-friendly option.


No matter your budget, we have replacement windows that perfectly fit your home and offer superior protection while eliminating drafts. Our MountainView replacement options are available in various styles, including slider, casement, awning, double-hung, and more to complement your home’s style.

One Stop Home Improvement Shop can help with all your home improvement needs, whether you need help with an insurance claim or a quote for installing a new roof or gutter system. We’re here to help every step of the way throughout the entire process. Contact us today for a free consultation!