“Possessing a profound knowledge of architectural history and theory, and embracing the avant-garde, he never merely replicated the status quo,” said the Pritzker jury in its citation, which also noted Mr. Isozaki’s support for young architects. “But his search for meaningful architecture was reflected in his buildings that to this day, defy stylistic categorizations, are constantly evolving, and always fresh in their approach.”

Born in Oita on the island of Kyushu in 1931, Mr. Isozaki came of age in a postwar Japan that was “in complete ruins,” with an emperor demoted and social customs in flux.

“Air bombardment had destroyed many of the cities, buildings had vanished and there was only rubble on the ground,” he wrote. “However, Japan had already assimilated western modernization by that time. The only possible choice I had was to start from the ruins — the degree zero where nothing remained.”

After graduating from the architecture department at the University of Tokyo in 1954, Mr. Isozaki apprenticed with Kenzo Tange, the 1987 Pritzker Prize winner known as the father of postwar Japanese architecture.