Tornquist had interest in the political and artistic movements that promote social transformation; he was a pacifist and refused to carry out military service.
In 1967, together with Richard Kriesche and Helga Philipp, Tornquist signed the founding manifesto of the "Gruppo Austria", which aims to direct the Austrian culture towards new artistic languages.
Parallel to his artistic practices, he started his career as color consultant with a project for the Caffetteria dello Studente in Graz (1966, in collaboration with Arch.
Jorg Mayr), then gradually he began to deal with important architectural sites, among which stands out the incineration plant in Brescia (1996).
In 1987 Tornquist created a performance titled "Apartheid" in Graz, his home town, which was done with the express intention of raising public awareness towards all living forms.