Gerhard Kallmann, the architect who, with Michael McKinnell, designed Boston City Hall, a hulking, asymmetrical, Modernist building that has been widely acclaimed by architects for half a century though disparaged by many Bostonians, died on Tuesday in Boston. He was 97.

His death was confirmed by Mr. McKinnell, who co-founded what was known as Kallmann, McKinnell & Knowles in 1962, the year their fledgling firm rattled the architectural community by winning a national competition to design Boston City Hall. It was the first of many grand edifices they would conceive. The firm is now Kallmann, McKinnell & Wood.

An example of the New Brutalism style of the 1960s, Boston City Hall is a gray concrete structure influenced by Le Corbusier’s monastery at La Tourette, France — both of them attempts to render modern architecture as monumental as classical architecture. Set in a vast plaza in what was once a run-down section of the city, Boston City Hall is a composition of irregularly protruding concrete boxes resting on slablike columns with row upon row of windows lining its overhanging upper floors....