WASCO Windows opened in Milwaukee in 1957 as Wisconsin Aluminum Supply Company, and was purchased by Dave Paulus in 1983. At that time, the company manufactured aluminum storm windows, siding and awnings.  Under Paulus’ direction WASCO became the first company in this area to manufacture then-new vinyl replacement windows. Since 1983 the Paulus family has transformed WASCO into a company that leads the industry in manufacturing and installing highly energy efficient window products, engineered for Wisconsin’s unique climate.

In 2012, WASCO fabricated the first American-made version of an energy-efficient, environmentally friendly window system that achieves European Passivhaus standards – and far exceeds North American Energy Star standards using the GENEO™ System (pronounced gun-a-oh) of windows and doors, developed by the German company REHAU, world renowned for its ground-breaking technology and the unmatched quality of its doors and windows.

WASCO's business is approximately 85% premium residential replacement windows in the Milwaukee and Fox River Valley areas. These windows are sold by WASCO's salespeople, built in WASCO's factory and installed by WASCO's carpenters. The remaining 15% of WASCO's business is high performance windows for high-end residential construction.