PPG Industries will donate more than 1,900 square feet of Starphire ultra-clear glass to restore 319 windows at Fallingwater, Frank Lloyd Wright’s architectural masterwork in Mill Run, Pa.

The Western Pennsylvania Conservancy, owner of Fallingwater, said the five-year project will replace window glass that has become cloudy and lost its ability to filter ultraviolet (UV) light from constant exposure to moisture and high humidity at the home’s signature waterfall setting.

The Starphire glass will be combined with a UV interlayer from DuPont. TRACO will laminate and assemble the windows. All three companies are donating their materials and services.

The original windows for Fallingwater, which was built in 1936, were made from quarter-inch PPG plate glass. They were replaced in the late 1980s by windows made of laminated PPG glass with a UV interlayer to protect the house’s art and furnishings.

The window replacement project is being financed by a new Window Legacy Fund established by the Western Pennsylvania Conservancy. It hopes to raise $500,000 to pay for installation of the new window glass and to endow future glass replacement projects. Individuals who donate at least $500 to the fund receive a piece of the actual Fallingwater window they helped to replace, along with a framed drawing of the house indentifying the window they endowed. So far, the fund has raised $150,000