He was most active in his home city of Lyon, where he notably designed the Halle Tony Garnier and Stade de Gerland.

[1] During his stay in Rome he began working on the project of an industrial city that became his main contribution to town planning.

[2] In 1901, after extensive study of sociological and architectural problems, he began to formulate an elaborate solution to the perceived issues concerning urban design.

His basic idea included the separation of spaces by function through zoning into several categories: industrial, civic, residential, health related, and entertainment.

Garnier's drawings for an ideal industrial city called Une cité industrielle were initially exhibited in 1904, but only published later in 1918.