U-Values Explained

The U-Value on a door or window measures how quickly the heat from the inside leaks to the outside. The lower the U-Value the better insulated the door or window is.

When calculating U-Values the glass and frame have to be considered. We offer a wide range of specifications with our lowest U-Value at 1.2W/m²k for our flush casement windows, and as low as 1.1W/m²k for our sash window range.

U-Value Certificates

Please click on the link to download.

High Performance Casement Window

BR 443 Model Sliding Sash Spiral Balance Window

 BR 443 Model Sliding Sash Weights and Pulleys Window

Type 2 Partially Glazed Hardwood Door with Insulated Panels