Compiled by Charles A. Evers and initially published in May 1997 inThe Philadelphia Architect.
There is growing interest in identifying and protecting important examples of twentieth century architecture. In a city such as Philadelphia, it is becoming a concern to architects, preservationist and architectural historians, as significant post-war buildings are being recycled to new uses or removed and replaced. Many of these structures have reached or passed their original life cycle, that is, they are in need of major renovations and replacement of obsolete systems. Many are contaminated by hazardous materials such as asbestos, and have difficult preservation requirements, such as the conservation of poured concrete or curtain walls. They are also often thought of as not as important or distinguished as 18th and 19th Century buildings. Philadelphia may not have distinct districts of 20th Century buildings, like those found in Miami or Los Angeles, but it does have many distinguished structures, several of which are of national and international significance.

The unique problems confronting the preservation of modern architecture, particularly the work of the early international architectural movements of the 1920's and 30's, was recognized ten years ago by University of Technology in Eidhoven, the Netherlands. There, architects and preservationists had recognized the special and difficult preservation issues found in buildings built between 1915 and 1945. Many of these buildings were constructed on limited budgets, with non-traditional techniques and materials, and were thought of as having limited life-spans. In 1988, the university began cooperative work with organizations, principally in northern and eastern Europe, that had encountered similar problems. The result was the founding of "the international working party for documentation and conservation of buildings, sites and neighborhoods of the modern movement," shortened to DOCOMOMO. The objective of DOCOMOMO is the preservation of buildings of the early modern movement (between the World Wars), the advancement of an effective inventory, and documentation and preservation of the most important Modern Movements buildings, sites and neighborhoods of that period.

Though the organization continues to concentrate on buildings from the 20's and 30's, the DOCOMOMO Journal has published articles that highlight the origins of modernism in the work of original thinkers of the previous decades, and has expanded its scope to the work of the architects involved in the reconstruction of Europe of after World War II.

Nina Rappaport, of DOCOMOMO/US, wrote in her 1994 article Preserving Modern Architecture in the USA, about the increased importance and awareness of the preservation of modern architecture in the United States. She saw this evolution in the thinking of preservationists symbolized by the acquisition of modern buildings by two stalwarts of the traditional preservation movement, the National Trust for Historic Preservation (Frank Lloyd Wright's Pope-Leighey House and Philip Johnson's Glass House) and the Society for the Preservation of New England Antiquities (the Walter Gropius House). She also noted the importance of highway and Main Street vernacular modern architecture in American cultural history, and the growing interest in diners, gas stations and billboard buildings. Furthermore, in spite of the rule that a building needs to be at least 50 years old to qualify for listing on the National Register of Historic Places, by 1994, over 1000 exceptions had been made for buildings of exceptional significance.

Here in Philadelphia, the need for increased awareness in the value of modern architecture is highlighted by the increasing number of important modern buildings that are vacant or in the process of undergoing a change in use. The PSFS Building and the Bulletin Building are two important modernist buildings in this category. The reuse of many of the early skyscrapers in the Broad Street Historic District as hotels and apartment buildings is rumored and awaits verification. Other buildings now destroyed that might have been included on this list include the Prentiss Building (1970, Carroll, Grisdale and Van Alen, demolished 1995), the AFL-CIO Medical Services Building (Louis Kahn, 1956, demolished 1973) and the Fidelity Mutual Life Insurance Building/Meridian Building (1969, Vincent Kling & Associates, burned and awaiting demolition). Important recent successes are the acquisition of the ASTM Building by Moore College of Art and the AT&T Building by the City of Philadelphia, as well as the restoration of 30th Street Station and the United States Court House at 9th and Market Streets. Recently, the Preservation Alliance announced that it had assisted in the donation of the Fisher/Kahn House in Hatboro (Louis I. Kahn, 1960-67) to the National Trust for Historic Preservation as part of the Trust's Gifts of Heritage Program, which will allow the house to eventually be sold subject to preservation easements that will protect significant interior and exterior features of the building.

As a way of stimulating interest in modern architecture, and identifying buildings that could eventually be designated by county historical commissions, the Historic Resources Committee of the Philadelphia Chapter of the AIA has assembled the following list of buildings built in the Greater Philadelphia Area between 1930 and 1972 (25 years ago). The list is by no means complete, and most likely lacks many significant industrial, residential and commercial structures built in the eight county area during that period. Included on this list are a dozen buildings built after 1930 that were identified in the Historic Architectural Inventories of Lower Merion Township compiled between 1985 and 1991. The buildings below are listed by date, and are in Philadelphia unless noted.; last rev. 25 June 97