Energy Star 7.0 - Updated Criteria for Windows & Doors

Where does Energy Star come from?

The Environmental Protection Agency (EPA) administers this government backed rating system that gives consumers an unbiased standard to go off when purchasing products for a home or building. The energy star label is different than the NFRC sticker. Windows are just one of the many products within a home that you can find energy star labels for. The new criteria (version 7.0) for energy star windows and doors represents an improvement of thermal performance. Which means lower u-values and slightly lower SHGC. This new version goes into effect on OCTOBER 23, 2023. This means that window manufactures will need to specify which windows qualify and which do not qualify to the new standard starting on October 23rd.

Most are familiar with the term “energy star windows” - but what does that really mean?

The US is split into four climate zones: Northern, North-Central, South-Central, and Southern (See map below). Each zone has different u-factor and Solar Heat Gain Coefficient (SHGC) requirements in order to meet the energy star label. Northern zones require lower u-values while the southern zones require a lower SHGC. This has led to some confusion for consumers as to whether or not the windows they purchase actually are energy star for their specific climate. Currently, you can walk into a box box store and purchase an “energy star” labeled window but that doesn’t necessarily mean it meets the performance criteria for your climate zone. You have to be aware of which climate zone you’re in and what the u-value and SHGC is for the window you’re purchasing.

The new energy performance requirements for each climate zone are outlined below. Notice that climate zone 4 has a prescriptive method allowing for more flexibility when picking windows in this climate zone. Allow me to explain this feature. The higher the U-factor is, the higher the SHGC must be. This is because you are making the window less insulated. However, at the same time you are allowing more solar heat in to "even it out". Take the first row for example; if you a U-factor or .22 or less then your solar heat gain must be .17 or greater. On the flip side if you have a U-factor of .26 and a SHGC of .50 (letting in 50% of the solar heat) or greater, then the window would also be energy star certified.

Can you buy Energy Star windows with only dual pane glass?

The answer is yes! Every manufacture is different in their offerings so be sure to ask about this next time you are ordering windows. Just to provide an example of a glass coating combination in the northern climate zone... you will want a passive solar coating along with a room-surface low-e coating. Cardinal Glass would call them "Low-E 180" & "Low-E I89." More than likely, you can get the windows to qualify with a similar-quality low-e coating combination. Lastly, of course if you went with triple pane glass, then you can hit those requirements in any category.

To read the full description of this announcement and related specifications (like for doors and skylights), please visit the energy star program requirements webpage.

Quick note on federal tax credits… to qualify for the window credit, the windows MUST be Energy star rated for your specific climate zone. READ HERE for more information regarding federal tax credit incentives.