Every complete Windsor unit is tested to meet the air, water and structural requirements of industry certification including AAMA (American Architectural Manufacturers Association) and NFRC (National Fenestration Rating Council).
Design Pressure (DP) is a measure of the structural performance of a window or door. For a product to be DP Certified, it must meet AAMA and NFRC testing requirements. The design pressure rating is generally one-and-a-half times greater than necessary to withstand any expected wind or weather condition.
With advanced engineering, you are assured that Windsor products are some of the most durable, high-performing windows available.