What is a wall anyways? What should it do? If you answered that it should hold up the roof, you would be right-if you lived before 1900.

‘Curtain walls’ are exterior walls that do not carry the weight of the building (the internal structure does). This allows us to subtract material from the outermost walls and lightens the overall aesthetic of the building. Although one could replace that non-loadbearing material with anything, glass was the material of choice, following the Industrial Revolution. By removing the mass of the walls, the architect is able to lessen the material and philosophical distance between interior and exterior. Curtain walls in contemporary architecture are engineered to be a more flexible design (literally) by dealing with more structural stressors (wind/seismic forces); thermal efficiency and lighting into the interior of the building.

The concept of the curtain wall dates back to the 1800s but took several decades to engineer it to the version that is ubiquitous in our contemporary buildings. The curtain wall is an old form starting initially at the turn of the 20^th century, predominantly in the context of exhibition architecture, such as the Crystal Palace. Although it was hugely popular with the general public at this time, it was largely still seen as a novelty rather than a mainstream building form.

It was not until the years just prior to World War II that the academic architects began to try and use curtain walls in mainstream architecture. The origin of curtain walls in academic settings is attributed to the Bauhaus and the inception of the International Style of modern architecture. This is mostly famously seen in the architecture of the Bauhaus School in the structure of the actual school. The European Modernists wanted a new aesthetic to accommodate a new modern lifestyle, which meant employing new cutting-edge technologies. The curtain wall is one of the central points of Le Corbusier’s 5 points of Modern architecture, a guide on how the new style of architecture for the post-WWII world. Although European architects were rudely interrupted by the outbreak of the War, many emigrated to the United States and this is where our story begins.

The Seagram Building is the pinnacle of corporate mid-century modernism. Designed by Mies Van der Rohe in 1958, this tower stands at 375 Park Avenue, in the heart of Midtown Manhattan. It was built to be the headquarters of the Seagram Company, a Canadian distillery, as well as the glamorous site of the Four Seasons restaurant. The Seagram Building represents the pinnacle of corporate glamour in the 1950s such that one might expect Don Draper to come out of the elevator at any time. The Seagram Building ultimately set the tone for New York skyscrapers in a new era of American prosperity. Standing at thirty-eight stories high, Mies employed a steel frame to hold up the interior of the building. He also used non-structural bronze I-beams and sheets of glass on the facades in order to emphasize the verticality of the building and create the illusion of a graceful black monolith. By utilizing luxury items on a monumental scale, the Seagram Building was one of the most expensive skyscrapers at the time of its completion. From the offices in the higher levels of the building, one has the sense of floating over the New York skyline. This effect could not have been achieved without the use of the curtain wall.

‘The Glass House’ is another example of curtain walls but this time, the avant-garde has entered the domestic sphere. American architect Philip Johnson designed The Glass House (and the adjacent ‘Brick House’) as his own private residence in New Canaan, CT.  Built in 1949, the Glass House technically pre-dates the Seagram Building but was strongly influenced by a house that Mies had built in Plano, Illinois between 1945 and 1951. The house is essentially a glass cube: there is glass on all four sides of the structure (though it is largely hidden from the street). In the same way that there is a diminished separation of interior and exterior, there are no walls between kitchen and entertaining spaces. It overlooks a pond and the large windows offer the viewer a spectacular panorama the estate.

Both buildings represent innovative softening of an avant-garde form for public consumption. Seagram Building represents the successful integration of the  curtain walls into the mainstream. The building is the visual representation of the Seagram Company and can be used to foster the image of modernity and glamour, prosperity as well as literal transparency. The Glass House is also a beautiful artistic piece in which curtain walls are utilized to spectacular dramatic effect. However, both buildings are also imperfect. Out of all the buildings in New York City, the Seagram Building has the worst Energy Star rating and is thus not environmentally sustainable. The Glass Building, though interesting from a conceptual standpoint would not be practical as a mass-housing project as it is hard to maintain privacy. Nevertheless, curtain walls are still being employed in our contemporary architecture and are still evolving and being better engineered to handle the stressors of modern life.

(Cover photo: Lobby of the Seagram building, Ezra Stoller)