Ordinary windows are built on lightweight frames made from recycled vinyl. These frames sag, warp, and crack when the walls flex and shift in response to changes in temperature. By law, these windows cannot be used in structures with more than three floors. Commercial grade windows, on the other hand, are built to bear the burden of structural shift, and to perform for decades without cracking or changing shape. That's why we build every window to meet that standard—we design it to last.
All of our windows come with fully rust-proof hardware, made by American workers. We guarantee that it'll work just as well as it did on the day it was first installed, for the life of the window.
The numbers are absolutely clear: we are selling the most efficient double-pane window you can buy.*
Glass pack: Energy Star 6.0
Window: Energy Star 6.0
NFRC Authorized Certification: Certified in all categories
* Testing performed by Keystone Certifications in 2016.