Guides

Matching a window spec to your climate zone, not just your budget

How to Read an NFRC Window LabelFour numbers on one sticker decide most of a window's real-world performance. Here's what each one means.
ENERGY STAR Window Criteria by Climate ZoneENERGY STAR splits the country into four zones, each with its own numbers. Here they are, and why the Northern zone works backward from the other three.
Impact Windows vs. Shutters in Florida's Hurricane ZonesFlorida gives homeowners two paths to a protected opening. Here's how each one is tested, and where the HVHZ raises the bar further.
Low-E Coatings and Gas Fills: What They Actually DoTwo features hiding inside the glass do more for performance than most people expect. Here's the mechanism behind each.
Why Windows Fog or Sweat: Understanding CondensationCondensation on a window is usually a humidity story, not a defect story, and new windows can make it more visible, not less.