Hugh Newell Jacobsen, Famed Modernist Architect, Dies at 91

Mr. Jacobsen’s scope was international, but he was probably best known for his prolific projects in the Georgetown neighborhood of Washington, where he lived and had his office. Starting in the early 1960s, he worked on more than 120 houses — a mixture of new construction, renovations (including the partially detached townhouse where he lived, which he had originally designed for someone else) and additions that emphasized space and light.

In Washington, he was also known for working on two Smithsonian museums: He did the preservation design of the Arts and Industries Building and the interior restoration of the Renwick Gallery. He also designed the west terrace addition of the Capitol and the Moscow residence of the United States ambassador to Russia.

Mr. Jacobsen was an unabashed fan of Washington, where he first lived as a teenager during World War II when his father, John, was an official of the War Shipping Administration.

“This city has wonderful colonnaded spaces that no one ever gets to see,” he told The New York Times in 1984. “The elegance of the Postmaster General’s office is cheering, just plain cheering. Washington is filled with this kind of stuff. When you look at a city, it’s like reading the hopes, aspirations and pride of everyone who built it.”

Mr. Jacobsen was born on March 11, 1929, in Grand Rapids, Mich. His father was a meat importer; his mother, Lucy (Newell) Jacobsen, was a homemaker.

“I always could draw, rather well, and painting I really loved to do,” Mr. Jacobsen told his son John in an interview in 2010 for “The Artist Toolbox,” a public television series.

After graduating from the University of Maryland in 1951 with a bachelor’s degree in fine arts, he hoped to become a painter. But his father steered him toward architecture, reasoning that it combined art and business. Mr. Jacobsen agreed and earned a certificate from the Architectural Association School of Architecture in London in 1954 and a master’s degree from Yale University, where he studied under the influential Louis Kahn, a year later.