Curtain Wall - History

History

Prior to the middle of the nineteenth century, buildings were constructed with the exterior walls of the building (bearing walls, typically masonry) supporting the load of the entire structure. The development and widespread use of structural steel and later reinforced concrete allowed relatively small columns to support large loads and the exterior walls of buildings were no longer required for structural support. The exterior walls could be non-load bearing and thus much lighter and more open than the masonry load bearing walls of the past. This gave way to increased use of glass as an exterior façade and the modern day curtain wall was born.

Rigid structures needed for curtain walls can also be made with wood, but tall trees had been scarce in western Europe since the Middle Ages. So when larger glass panels were being created during the 18th century, the first true curtain walls were built in the Ottoman empire, where wood construction was still at a high, and not in the Industrializing west.

Oriel Chambers in Liverpool, England, was the world's first metal framed glass curtain walled building in 1864, followed by 16 Cook Street, Liverpool, in 1866. Both buildings were designed and built by local architect Peter Ellis. The extensive glass walls allowed light to penetrate further into the building utilizing more floor space and reducing lighting costs in short winter months. Oriel Chambers comprises 43,000 sq ft (4,000 m2) set over a maximum of five floors as the elevator had not been invented.

Some of the first curtain walls were made with steel mullions and the plate glass was attached to the mullions with asbestos or fiberglass modified glazing compound. Eventually silicone sealants or glazing tape were substituted, using a glass mullion system. Some designs included an outer cap to hold the glass in place and to protect the integrity of the seals. The first curtain wall installed in New York City, in the Lever House building (Skidmore, Owings and Merrill, 1952), was this type of construction. Earlier modernist examples are the Bauhaus in Dessau (1926) and the Hallidie Building in San Francisco (1918).

The 1970s began the widespread use of aluminum extrusions for mullions. Aluminum offers the unique advantage of being able to be easily extruded into nearly any shape required for design and aesthetic purposes. Today, the design complexity and shapes available are nearly limitless. Custom shapes can be designed and manufactured with relative ease.

Similarly, sealing methods and types have evolved over the years, and as a result, today’s curtain walls are high performance systems which require little maintenance.