Tom Shafer

Energy Star 6.0 windows

January 20, 2015

On January 1st, 2015, Energy Star 6.0 took effect. What does that mean for you? Well, if you're buying new windows or doors this year, it means you'll be able to get top-of-the-line products that are more energy efficient than ever before. Before we dig into the nitty-gritty, take a look at the map below detailing the Energy Star Climate Zones. It's split into these sections because Energy Star knows that a home in Louisiana and a home in Maine aren't going to need the exact same kind of windows. The weather in your region impacts the product you need.

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energy star climate zones

Energy Star 6.0 is the newest set of requirements for energy-efficiency. The new criteria require lower u-values in the North Central, South Central, and Southern Climate Zones, while the South Central and Southern Climate Zones also require a lower solar heat gain coefficient (SHGC). The Northern Zone is exempt from the change for 2016.

If you've never shopped for windows before, those terms may not mean anything to you. So let's look at a quick breakdown of the lingo:

  • U-value is a number that tells you how well the window glass resists the flow of heat from inside your home to outside. The lower the u-value, the better it is at keeping heat inside.
  • SHGC measures the solar radiation that comes in through your windows and is released as heat inside of your home. You can think of this almost as the opposite of u-value; u-value measures heat escaping and SHGC measures heat coming in. The lower the SHGC, the less heat you have coming into your home.

So if you live in the North Central, South Central, or Southern Climate Zones, and you want a window that meets the newest Energy Star requirement, the new requirements mean you'll be buying a product that keeps heat (say, from your furnace) inside your home where you want it. Those in the South Central and Southern Zones have an additional requirement that windows be better than ever at keeping heat from the sun from impacting the temperature inside your home. In a nutshell: a warmer home in the winter and a cooler home in the summer.

There are many ways that manufacturers meet these requirements: low-e glasses, window glass with an argon gas infill between the panes, insulated frames, etc. For example, in 2015 in the South Central and Southern Climate Zones, windows with low-e3 glass and an argon infill meet most criteria. In 2016, the same zones will need low-e3 glass with a lower SHGC plus an argon infill to meet the requirements. Here's a comparison chart to get an idea of how requirements are changing:

energy star 2015 requirements

The type of window you're replacing can also make a difference as to what characteristics it needs to meet Energy Star requirements. For example, almost all patio doors now need an argon infill to meet the new criteria.

When you are replacing you windows or doors, I recommend you meet the new Energy Star requirements. There are so many reasons to spend the extra money on these windows. Meeting this criteria can help you sell your home by advertising that the windows are fully up to energy code requirements, you save on energy costs, and most of all, you make your home more comfortable in summer as well as winter. A quick note for anyone buying windows from a Big Box retailer: they sometimes get a smaller margin of profit on windows that meet current Energy Star Requirements and so may not recommend them to you. But you know better now.

Wherever you shop for your windows, make sure you're dealing with an expert window contractor, and ask them for windows that meet Energy Star requirements. You'll be getting an excellent product that helps your home do its job best.

Credit for Climate Zone Map and Qualifications by Zone chart to Energy Star.


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