Neumann was born in Cheb (Eger), Bohemia. He moved to Würzburg in 1711 and became a patron of the Schonborn family in 1717. In Würzburg he built the Residenz, residential palace of the Schonborn prince-bishop of Würzburg. He died in Würzburg, Germany.
A picture of him could be seen on the former 50-DM note together with the famous staircase located in the Residenz of Würzburg.
He traveled (1718) in Austria and N Italy and studied (1723) in Paris.
Neumann designed several palaces and churches in Würzburg, some of which were decorated by Tiepolo.
In 1742 he began the planning of Vierzehnheiligen, the most famous rococo church in Germany, celebrated for the sumptuous architectural decoration of the interior and the brilliant spatial arrangements within a series of oval spaces.