Ralph Rapson, FAIA, regarded as one of the foremost architectural draftsmen of the 20th century and Minnesota’s premier Modern architect, died of heart failure on March 29 at his Minneapolis residence. He was 93 and still working at his office the day before. “For him, it wasn’t really work, it was what he enjoyed the most. He was drawing a cabin and making furniture designs,” says his son Toby, president of Rapson and Associates. Drawing was one of Rapson’s special talents and professional trademarks, despite the loss of his right arm, which was amputated during boyhood. He used his left hand as deftly as any artist.

As dean of the University of Minnesota School of Architecture for 30 years, and designer of the original Guthrie Theater, completed in 1963, Rapson became an inspiration for hundreds of graduates who founded their own firms. The Michigan native graduated from the University of Michigan in 1938, then studied at the Cranbrook Academy of Art under Eliel Saarinen, working with noted designers including Charles and Ray Eames, László Moholy-Nagy, and Alvar Aalto. Later he joined the Saarinen architectural office. While at Cranbrook, he also began designing furniture. The popular “Rapson Rapid Rocker” debuted in 1945 as part of the Knoll furniture line and has since been re-issued.

Thoroughly imbued with Modernism, the new materials and technology, Rapson moved to Chicago in 1941 and began his illustrious career. There he designed one of the first Case Study houses: Case Study House No. 4, the “Greenbelt House.” The iconic 1,800-square-foot residence includes a central interior enclosed by a translucent wire-glass roof, intended to bring nature indoors. Some four decades later it was rebuilt for an exhibition at the Los Angeles Museum of Contemporary Art—and, recently, his office designed a line of prefabricated modern houses, “The Rapson Greenbelt,” based on one of his original 1941 designs.

Rapson joined the faculty of the Massachusetts Institute of Technology and by 1951 was recruited to design the first modern American embassies in Europe, including those in Stockholm and Copenhagen. He came to Minnesota in 1954 to head the university’s School of Architecture where he encouraged practicing architects to teach the challenges of the profession. Although his academic duties meant less time for running a practice, Ralph Rapson and Associates—staffed by his son Toby and recently his grandson Lane—remained productive. His work was recognized with many honors including five national awards from the American Institute of Architects; the ACSA/AIA Topaz Medal for Educational Excellence, in 1987; and five Progressive Architecture awards. Also, he was the first Minnesota Gold Medalist, in 1979.

By far Rapson’s best known building was the Guthrie Theater, designed for Sir Tyrone Guthrie, a brilliant but demanding client who clashed many times with the architect. The rectilinear building contained a unique thrust stage that jutted into its auditorium. Guthrie opposed Rapson’s desire to surround the stage with seating in a zig-zag pattern. Guthrie also objected to the building’s exterior design, which was clad by a Mondrian-like patterned screen made of plywood, intended to frame attendees inside a glass-walled lobby. In the end, Rapson prevailed and his design was praised as one of the most innovative theaters of the post-war era. Today, a similar thrust stage exists at the new Guthrie Theater, designed by Jean Nouvel—an homage to the original building, which was demolished soon after Nouvel’s work opened in 2006.

Tom Fisher, dean of the University of Minnesota College of Design, observes that Rapson’s passing marks the end of an era in American architecture. “Ralph was the last of the second generation of Modernists in America still practicing,” Fisher says. “He will be very much missed by the thousands of people he influenced.”

Throughout his married life, Rapson, sketchbook under his arm, and his late wife, Mary, often traveled abroad to see landmark buildings. Many delightful watercolors resulted, which his friends and legions of admirers have collected. He was a warm-hearted family man, customarily sporting a bow tie, ever-gracious to students and faculty alike. In addition to his son Toby, Rapson is survived by his elder son, Rip, who is president of the Kresge Foundation, and six grandchildren.