As a member of the Wiener Gruppe, he wrote concrete poems and experimental literature.

[1][2] He attended the Höhere Bundesgewerbeschule in Salzburg,[3] and then studied architecture at the Academy of Fine Arts Vienna from 1950 to 1953 with Clemens Holzmeister.

[1] In 1955, Achleitner joined the Wiener Gruppe, which had at its center H. C. Artmann, Konrad Bayer, Gerhard Rühm and Oswald Wiener [de], henceforth participated in its literary cabarets, and wrote poems in dialect, montages, and concrete poems.

[5] He began to work as an architecture critic for Austrian daily papers, from 1961 anonymously for the Abendzeitung,[3] then especially from 1962 to 1972 for Die Presse.

[4] In 1983, he was appointed professor of the history and theory of architecture at the University of Applied Arts Vienna,[1] a post he held until 1998.