Retaining Fallingwater’s Iconic Connection Between Indoors & Outdoors

In September 2019, the Western Pennsylvania Conservancy, owners of Frank Lloyd Wright’s Fallingwater, sought to complete restoration work on the window and door glass of the architect’s celebrated masterpiece. As it has done for many years, the organization turned to two trusted sources for their products and expertise: Vitro Architectural Glass (formerly PPG Glass) and Dlubak Specialty Glass Corp., a member of the Vitro Certified^™ Network. 

One of Wright’s primary goals in designing Fallingwater was to reduce, as much as possible, the visual barrier between the inside of the house and its iconic location above the falls of Bear Run in Pennsylvania’s Laurel Highlands. This guided Wright’s 1934 decision to specify Waterwhite glass, a low-iron glass that PPG Glass (now Vitro Glass) had recently introduced. Because Waterwhite glass is no longer made, the staff of Fallingwater today relies on its more sophisticated successor, Starphire Ultra-Clear^® glass, to preserve its fabled exterior views. Manufactured by Vitro Glass using a proprietary low-iron formulation that continues to be refined, Starphire^® glass has been chosen for all of Fallingwater’s window glass replacement projects over the past few decades.

^{One of Wright’s primary goals in designing Fallingwater was to reduce, as much as possible, the visual barrier between the inside of the house and its iconic location.}

^{Photography courtesy of Western Pennsylvania Conservancy}

Fallingwater is the only major work by Frank Lloyd Wright to be brought into the public domain with so much of its original furnishings and artwork intact. While regular maintenance is performed to keep it in prime condition, its caretakers work diligently to ensure that all efforts to preserve the property are made with his legacy in mind.

Window and door restoration is a continuous task, says Scott W. Perkins, director of preservation and collections for Fallingwater. “The window glass is replaced on a somewhat routine basis and usually in conjunction with steel conservation,” he explained. 

Although the last major round of window preservation took place in 2015, the Conservancy determined in September 2019 that 69 of Fallingwater’s window and door sashes needed to be repaired, including 16 windows that required complete replacement of the glass. 
To enhance the strength and performance of the refurbished windows while preserving their historic integrity, the Conservancy specified Starphire^® glass with a SentryGlas^™ interlayer by Kuraray. In addition to offering five times the strength of ordinary laminating materials and 100 times the stiffness, the interlayer helps protect furnishings by limiting their exposure to ultraviolet (UV) light.

While the interlayer gives strength to Fallingwater’s window glass, Starphire^® glass preserves its beauty. With visible light transmittance (VLT) of 91% in a standard ¼-inch (6-millimeter) thickness, Starphire® glass delivers the virtually unobstructed outdoor views Wright envisioned for Fallingwater when he first specified Waterwhite low-iron glass in 1934. “The clarity of the glass allows for it to appear invisible, a feature Wright admired,” Perkins explained.

Nearly 25 years after Starphire^® glass was introduced, it remains the clearest, most transparent commercial float glass available to architects today – containing 87% less green than ordinary clear glass and offering pure, undistorted transmitted color with absolutely no grays or yellows.

To learn more and request samples, visit www.vitroglazings.com/starphire.