Born 1928 in New York, Rossant attended the Bronx High School of Science before receiving a bachelor’s of architecture from the University of Florida in 1950, then under the leadership of Paul Rudolph. “Rudolph took my dad under his wing,” says Tomas Rossant, AIA, now a partner at Polshek Partnership, “and he said, you already have an architecture degree, now you should study planning.” Rossant moved to Harvard Graduate School of Design, where he received his master’s in urban planning in 1953. James Rossant, architect, illustrator, and planner, died at his home in Normandy, France on December 15, 2009. The cause was complications from leukemia. His wife, food writer Collette Rossant, survives him, as do his children Cecile, Juliette, Marianne, and Tomas, as well as eight grandchildren.
Rossant served in the Navy and worked with Italian architect Gino Valle before returning to New York, where he started work for Mayer, Whittlesey & Glass. There, he met William Conklin, with whom he would lead the firm after 1967 under the name Conklin and Rossant. The partnership lasted until 1995, when Rossant founded James Rossant Architects.
In a 2005 essay, Conklin recalled meeting Rossant while working on Butterfield House, an apartment building in Manhattan’s West Village neighborhood. He wrote of Rossant: “At heart, he is an artist, a great artist, and we instantly became allies.” Butterfield House won numerous accolades and is still held in high regard for its synthesis of a Modernist vocabulary with sensitive, human-scaled details.
Rossant’s most notable work came in the form of large-scale planning efforts, such as his 1963 plan for the new town of Reston, Virginia, outside Washington, D.C.
Rossant designed the first neighborhood of Reston, Lake Anne Village, to resemble Portofino, Italy, organizing it around a town square. The project was seen as an intelligent response to the then emerging problem of suburban sprawl.
In addition, Rossant carried on a long career in academia, teaching at the Pratt Institute, NYU, and Harvard, among other schools. He was also a prolific illustrator, producing vivid drawings in support of his planning efforts—perhaps most notably his 1966 drawings for Lower Manhattan, which provided a vision far ahead of the district that exists today. In 2009, he published Cities in the Sky, a collection of architectural drawings and paintings.
In the end, it was the planning projects that  “really captured his heart,” according to his son, Tomas. “He was proud of the Lower Manhattan plan, but more importantly he was hired by UN to design new capital of Tanzania. They never had enough money to do it, but he spent five years on it. He was a capable architect, but he could think about large scale urbanism and he delighted in both those scales.”