“Every structure that I have built has been a ‘first’ for me—I have refused to emulate any existing form or idea.” So wrote Gunnar Birkerts in the preface to a 2009 monograph of his work. The Latvian-American architect died yesterday at the age of 92 from congestive heart failure. He will indeed be remembered for his original, and often unusual, buildings that extended the boundaries of the Modern movement.

Considered part of a second wave of foreign-born modernists in the United States, Birkerts came to prominence in the 1970s. He began his studies in architecture as a ‘displaced person’ at the Technische Hochschule in Stuttgart, Germany just as World War II ended. There, studying with Rolf Gutbrod, Birkerts trained under a strong Bauhaus curriculum. “We had a faculty of Bauhaus people there. And right across the street, practically, from the college, from our building, was the Weissenhof—an arrangement of buildings by all the Modernists,” Birkerts recalled in a 2014 interview. “There was Mies van der Rohe, Hans Scharoun…everybody had a building. It was almost like a village. So this thing was sort of absorbed, inhaled.”

After coming to America and showing up unannounced at Eero Saarinen’s office, he completed a brief apprenticeship in the Chicago office of Perkins + Will from 1950-51, until Saarinen was able to hire him. He worked there for several years, an experience he referred to as both “destiny” and “profound.” He would later become chief designer at Minoru Yamasaki’s firm before founding his own practice in the Detroit area in the early 1960s.

The project that put Birkerts on the map was the Federal Reserve Bank in Minneapolis (1967-73), which pioneered the structural use of suspension bridge principles. It was the first of many collaborations, and start of a close friendship, with structural engineer Leslie Robertson, which would span five decades. “He walked into my office without an appointment and asked me if I knew who he was,” Roberston recalls. “I said, ‘Honestly, I’ve never heard of you before in my life.’ I guess that established a relationship in which he knew I wouldn’t sugarcoat things.” Though Birkerts originally designed the building with many catenaries, Robertson reduced them to just one. Later collaborations included the Corning Museum of Glass (1980), with its curved and faceted steel-coated glass façade, and an addition to Uris Library at Cornell University (1983), which, like his addition to the law library at the University of Michigan, is mainly below grade. “Unlike the way most architects and engineers work, ours was a very conversational approach,” says Robertson. “He was a very cool guy—very laid back but very convincing. And he had a wonderful voice and smile.”

Birkerts’ work was hard to categorize, and ran the gamut from mega-structures, like his masterplan for Tougaloo College in Mississippi (1965-72), which was only partially built, to the diminutive but powerful St. Peter’s Lutheran Church in Columbus, Indiana (1988), which was both circular and orthogonal in plan. Another radial structure, the Boyd Law Building at the University of Iowa (1986), is considered by some a Postmodern design because its central dome over a cylindrical base seems to reference nearby grain silos and the Old Capitol. But Birkerts would strongly disagree, saying that Postmodernism grew from a certain boredom where architects “ran out of things and used the old cliché of appliqué.”

“He was always looking, searching, thinking,” says Marlene Imirzian, FAIA, who began working in Birkerts’ office while still in high school and is part of a strong network of former employees, including Will Bruder, that remained in touch with Birkerts. “He never brought a past idea to a new project. That was very powerful for me—and I had no idea it wasn’t how most architects worked!”

Though Birkerts arrived in Michigan when it was a hotbed of design, his choice to maintain his practice there after its heyday may have prevented him from attaining more international renown—that and the idiosyncratic nature of his designs. He traveled frequently to Italy, where he owned property in a small town north of Rome called Civita di Bagnoregio, and while he had projects in development in Milan and Turin, none were ever realized.

In his later years, when Birkerts moved to Massachusetts to be closer to family, he received his most personal commission, for the Latvian National Library in Riga (1989-2014), the city of his birth. The project—a craggy glass mountain that refers to Latvian folklore and which was much delayed over financing issues—consumed him. “Just as he was supposed to be happily retired, he was obsessively involved in the design,’ says son Sven Birkerts, who worked on the 2009 monograph, Gunnar Birkerts: Metaphoric Modernist, with co-author Martin Schwartz. The elder Birkerts brought his wife, three children, and seven grandchildren to the official opening of the building in 2014, attended by the country’s president. Says Sven, “It was a capstone family event—a symbolic closure, and a homecoming.”