In this new construction I found that these windows are Energy Star inferior, by any measure.
This is a beautiful, zillion $ house, with the builder claiming Energy Star all over it.
I noticed that I could feel the sun through a bedroom window. The day was not particularly warm, in the 60s. But if you can feel warmth through a window at this time of year it is not the superior window one might expect in a house like this.
However, all the window performance stickers had been removed. Except one!
It was located over the master bathtub.
The tub was full of the protective plastic and cardboard, and someone did not want to get in there yet to remove the window sticker.
Taking a photo and asking my client if this was the kind of sticker seen elsewhere, he said that he had taken photos of a couple of the other window stickers.
Indeed, they were the same!
If the windows really do have the same rating as this window, then they do NOT meet the Energy Star criteria for windows in our area. The arrow on the right in the photo points to the Energy Star Partner rating, meaning this window manufacturer does make windows to Energy Star ratings. (I have had supervisors point to that to say and pretend that the windows are Energy Star windows...)
What makes windows, and doors, Energy Star compliant? The National Fenestration Rating Council (see the logo with the sun on the upper left of the label?) tests and determines the ratings for various manufactured products. Fenestration is an architectural term for the arrangement of windows and doors in a house. The NFRC is the rating agency.
The two critical numbers are circled in red. They are painfully high, which is why I felt the sun through the window. The left is the U-factor, and the right the SHGC (Solar Heat Gain Coefficient). The U-factor divided into 1 gives you the R-value for the window. The Energy Star R-value for Virginia would be 3.3 or better.
To meet Energy Star those numbers have to meet the criteria set for the area where the house is located. You can see the page here, and look at the chart. Virginia is in the North Central. As such, to meet the Energy Star criteria the U-factor would have to be .30 or less, and the SHGC .40 or less.
THESE WINDOWS ARE ENERGY STAR INFERIOR, BY ANY MEASURE.
Asking the supervisor he claimed not to really know, but said that they use windows that "are better than the other builders," so he is sure there are good ones here. It's hard to know if he was blowing smoke or honestly ignorant.
My recommendation: see what your sales contract says in terms of energy criteria claims. To be labeled an "Energy Star House" the materials and installations have to meet very stringent criteria and have it so rated and labeled by an outside agency. Most houses DO NOT get that label. It would appear on the panel box if it did. But if the builder contract claims to use Energy Star "stuff," be sure the house contains it! A home inspector can help you determine if it does. And a pre-drywall inspection is the best time to check window and door installations!
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560