Preserving Modernism

Postwar Modernism’s most defining element – the glass and aluminum curtain wall – is also its greatest vulnerability. Designed as thin, industrialized systems, these systems now face failure and potential demolition due to aging materials, poor performance, obsolescence, and rising environmental demands. Preserving them requires balancing building physics, heritage conservation, and real estate pressures.

Following a concise history of the modern curtain wall, this publication presents selected case studies – from 100 Park Avenue (Kahn & Jacobs, 1949) and the Pfizer Building (Emery Roth & Sons, 1961) in New York to Great Arthur House in London (Chamberlin, Powell and Bon, 1957) and the Rotterdam Library in the Netherlands (Van den Broek and Bakema, 1983) – and analyzes rehabilitation, overcladding, and replacement as primary intervention strategies for curtain wall renewal.

Uta Pottgiesser, PhD is Professor of Building Construction and Materials at the Detmold School of Design at OWL, University of Applied Sciences and Arts (TH OWL) in Germany and Professor of Heritage & Technology at the Faculty of Architecture and the Built Environment at TU Delft in the Netherlands. From 2017 to 2019, she was Professor of Interior Architecture at the Faculty of Design Sciences at the University of Antwerp in Belgium. She has more than thirty years of experience as an academic in education and research, and as a practicing architect. In both roles, she is concerned with analyzing, protecting, adapting, and improving the built heritage and environment with a focus on 20th-century architecture. To advocate and promote awareness, she has been a member of DOCOMOMO Germany and, since 2008, DOCOMOMO International―where she served as Chair of the DOCOMOMO International Specialist Committee of Technology (ISC/T) from 2016 to 2022. Since 2022, she has been President of DOCOMOMO International representing more than 85 national working parties. As a member of the European Facade Network (efn) and cofounder of the international facade specialization within the Master of Integrated Design (MID) program at TH OWL, she actively promotes international exchange. Pottgiesser continues to be a reviewer and (co-)author of several international journal articles and publications with a focus on construction and conservation topics. She holds a professional degree as an architect (1993) and received her Diploma in Architecture (1991) from the TU Berlin, Germany. Her doctoral dissertation (2002) at the TU Dresden, Germany, was on the topic of “Multi-Layered Glass Constructions. Energy and Construction.” 

Angel Ayón, AIA, NCARB, NOMA, APT RP, QEWI, LEED AP is the founder and Principal of AYON Studio Architecture • Preservation, P.C. (AYON Studio) in New York City, where he provides comprehensive professional services in the fields of architecture and historic preservation. Ayón has more than thirty years of experience of learning from, advocating for, and ultimately conceiving and overseeing conservation efforts to save and secure our built heritage as a cultural asset for current and future generations. His experience with modern architecture includes the rehabilitation and exterior enhancement of Frank Lloyd Wright's Solomon R. Guggenheim Museum, for which he was the project architect between 2004 and 2008 (prior to founding AYON Studio). He is a member of, among other organizations, DOCOMOMO US and its local chapter DOCOMOMO-New York/Tri-State, the Historic Preservation Committee of The Municipal Art Society of New York, the Board of Advisors of the Historic Districts Council, and the Board of Trustees of the Preservation League of New York State―as well as Vice-President of Save Harlem Now! He was awarded the 2015 James Marston Fitch Mid-Career Fellowship. Ayón holds both a professional degree in Architecture (1995) and a MSc in Conservation and Rehabilitation of the Built Heritage (1998) from the Higher Polytechnic Institute José Antonio Echeverría in his native Havana, Cuba, and a Post-graduate Certificate in Conservation of Historic Buildings and Archaeological Sites (2002) from Columbia University in New York. 

Angel Ayón, NCARB, APT AP, QEWI, AYON Studio Architecture • Preservation, New York

Uta Pottgiesser, Professor at TH OWL; TU Delft; President Docomomo International