Alker studied in Karlsruhe from 1904-1911. He stayed in close contact with the Technical University working as an assistent. In 1920 he became doctor and in 1921 professor. He planned mainly housing estates in Karlsruhe.
When the Nazis seized power in 1933, he carved out his career. In Munich he became a city planning officer. However, since there were differences of opinion about styles with Adolf Hitler and after publishing an unauthorized article, he lost this position. From 1941 he was commissioned to transform Strasbourg into a district capital (German: Gauhauptstadt). Although he lost his positions in 1945, he was able to open his private architectural office in 1950.