Examination of Glass Transparency in Recent History

Despite its ubiquitous presence in contemporary architecture, glass transparency has seldom been examined deeply. Colin Rowe and Robert Slutzky’s 1963 classic essay “Transparency: Literal and Phenomenal” remains a tenet of architectural thought.⁹’¹⁰ Rowe and Slutzky consider the perceptual and compositional potential of transparency in painting and architecture but assume, rather than examine, its relation to materiality, specifically to glass. They define material transparency of glass as literal transparency, which they dismiss as unambiguous and limited in interpretations. Over time, the limitations of their binary understanding of transparency have been critically questioned.^11,12,13 The Light Construction exhibition of 1995, curated by Terence Riley at the Museum of Modern Art, investigated “the nature and potentials of architectural surfaces.”¹⁴ The survey of 30 projects notably brought attention to the extensive use of translucency in contemporary architecture. Concerned not only with the materials but the meanings they convey, the exhibit suggested that translucent materials become a veil that distance the viewer from the object. In 2007, Columbia University organized a multidisciplinary symposium on glass in architecture, entitled Engineered Transparency.The event and the accompanying publication spawned discourse around the impact of engineering and fabrication technologies on glass architecture.

The Book's Approach

In order to deepen and broaden readings of glass transparency, Blurred Transparencies explores the interweaving of the historical, theoretical, and cultural aspects of glass buildings along with the practical. Practitioners’ everyday concerns guide the chapters as well: technical details, material specification, structural and mechanical systems, budget, and constraints placed by the client. This book brings to light the complexities in the transparency of glass through close observations of six pivotal works of architecture, one modern and five contemporary. All are built with optically clear glass — not diffused or textured, which are in some ways inherently blurred - for their exceptional effects, which allows the focus to be on the qualities of transparency and reflectivity in glass. Each building has been selected to demonstrate how its glassy qualities transcend transparency as it has been understood in the discourse of modern architecture. Each chapter examines glass’s physical properties and assembly details, interwoven with an intricate web of social and cultural metaphors and historic precedents. The book is neither a comprehensive documentation of glass architecture — which Michael Wigginton has done masterfully - nor a theoretical examination of glass architecture situated in a particular city and time — such as Annette Fierro on François Mitterand’s Grands Projets in Paris,¹⁶ Deborah Ascher Bamstone on postwar Germany,¹⁷ or Isobel Armstrong on Victorian glass.¹⁸ Instead, Blurred Transparencies is written through the lens of a practitioner-academic, interweaving the historical and cultural with practical and empirical knowledge in the architectural uses of glass. The book demonstrates how transparent glass is rarely crystal clear, but is blurred both materially and metaphysically, exploring complex ideas for which glass continues to stand.

Six Buildings

Matter Infused with Spirit: Zonnestraal Sanatorium's Healing Glass Transparency

Designed by Jan Duiker and Bernard Bijvoet in Hilversum, the Netherlands, Zonnestraal Sanatorium (1931) was built as an aftercare colony for tuberculosis patients. It was built in accordance with a Dutch functionalism principal that architecture can fulfill a spiritual role beyond practical functions. Its physical and metaphysical lightness is underscored by the delicacy of glass membrane on thin steel frames, which wrapped the building like a drapery. These expansive windows brought in light, fresh air, and views of the surroundings to heal the recovering patients. Built with nearly colorless single-lite drawn glass, Zonnestraal serves as a baseline to gauge how contemporary glass buildings have become less crystal clear and more blurred. During the judicious restoration of the building in the early 2000s, the original glass was replaced with a combination of single- and double-glazed glass to meet the standards of current thermal comfort. Comparisons between the original glass sheet and the contemporary glass assembly offer an opportunity to study how the perception of glass changes over time.

Mirroring Ipswich: Contextual Class Transparency of the Willis Building

Willis Faber and Dumas Headquarters (1975) by Foster & Associates in Ipswich, UK made pioneering contributions to glass curtain wall buildings and the culture of workspaces. It blurred — or made less clear — the boundaries between the exterior and interior with reflective, frameless curtain walls. By suspending dark gray tinted and coated glass panels from concrete floors with metal corner patch plates, the faceted glass panels trace the irregularly curved streets of the medieval English town. In the daytime, the frameless glass becomes a scrim on which the masonry buildings across the intersection appear reflected and distorted. At night, the view on the façade is reversed: the transparent glass walls expose the illuminated interior like an X-ray. Additionally, with its expansive floor-to-ceiling glass walls, the Willis Building cultivated a new type of transparent landscape office architecture.