Riphahn studied at the technical universities in Berlin-Charlottenburg, Munich, and Karlsruhe.
He worked for a Siemens construction office in Berlin and in 1912 for "Gebrüder Taut & Hoffmann".
In 1913 Riphahn became an independent architect and worked with Caspar Maria Grod until 1931.
Some of his more well-known works include the Bastei restaurant and the Cologne opera house.
Riphahn is buried in Cologne's Melaten cemetery.