From 1906 - 1911 he studied architecture at the Prague Polytechnic (Pražská polytechnika). He also worked as a photographer and graphic designer.
In his work as an architect, like his peers, Hnilička started to use Art Nouveau, which was taught by his teachers during his studies. He soon turned to the Viennese geometric Art Nouveau and to the admiration of various styles of modern architecture. In the interwar period, he was one of the leading representatives of the art deco style, until he came to functionalism, the Czech version of modernism in architecture.