Ga-ga for Glass
November 27, 2008
During the late 1920s the German socialist architect Bruno Taut published a fascinating book on “glassarchitecture” that presaged the experiments of his countryman, Ludwig Mies van der Rohe only a few years later. Once Mies designed his signature glass curtain wall skyscrapers in Chicago, the potential magic of this new material was unleashed on the world. Architects have been spellbound by glass architecture ever since.
Engineering and building technology have lagged behind the visions of architects for centuries, but no material has proved as elusive as glass in testing the ingenuity of designers. Though it can provide abundant natural light in buildings, and makes an attractive exterior surface when properly handled, glass has many drawbacks as a building skin. It absorbs heat and ultraviolet rays, sheds water poorly, and is expensive to manufacture in large sheets. Moreover, it is structurally fragile, needing a backing framework in order to withstand wind loads and other natural hazards. In short, glass does not possess the qualities we look for in a tough, weather-resistant building skin.
Recent developments in “lightweight” structures have allowed designers to employ glass in new and often exciting ways. Thicker glass panels are now used as balustrades and “invisible” barriers for stairways and balconies. Architects have designed glass stair treads with little or no metal armature for support. And engineers have devised every more intricate multi-layer glass curtain wall systems that mitigate against heat gain and loss. Indeed, there is a kind of renaissance in glass technology that has brought the material back into vogue after decades of problematic and leaky curtain wall failures.
Despite these new developments, sustainable design standards suggest that buildings employ no more than 40% glass as an exterior surface in order to maximize the performance of the building envelope. This is about the percentage employed in classic tall buildings of the Chicago school during the 1890s and early 1900s. The Guaranty Building in Buffalo and Wainright in St. Louis are still among the most beautiful tall buildings in America.
I find it mystifying and unconscionable that architects continue to preach about energy efficiency while producing more and more all-glass (or virtually all-glass) buildings. The most recent issue of Architectural Record featured what may be the non-plus-ultra of such follies: the Kanagawa Institute of Technology Workshop by Junya Ishigami & Associates. The architect professed to be interested in blurring the boundaries between interior and exterior, even between structure and skin, in this frustratingly elusive building. Indeed, the students working at desks in the building must feel as if they are literally in a fishbowl, as there is no frame of reference that articulates the space they occupy.
The use of glass in the walls, with almost no suggestion of supports or frame, renders the building curiously boring and listless. In the evening, when clear glass buildings are most dramatic, the spaces inside appear vacant (no humans are shown in the photos) except for oddly placed desks and the inevitable clutter associated with workshops. The daylight photos in the article show that the building is unimpressive in an overcast environment and that the spaces do not benefit from fully-transparent outer walls when skylights provide ample interior illumination. In sum, this essay in “crystal” architecture proves that the modernist ideal of transparency is as elusive as ever. Even new technology cannot make up for the challenges of constructing a foolproof and beautiful “window wall.”
Why do architects continue to use glass as a monolithic material in walls, when it is clearly more effective as a covering for apertures? The likely answer lies in an irrational fascination with the crystal metaphor that Taut identified in his treatise almost a century ago. Pursuing a “crystalline” fantasy with technology resulted in some of the silliest and most wasteful architecture of the mid-20th century (now requiring vast capital expenditures for restoration). The current greenhouse fantasy is little different, and will undoubtedly result in a host of similar failures as we face a new challenge–energy efficient, resource miserly buildings for a planet that is roasting in its own conservatory of CO2, a glass-enclosed globe.