From April 1971 to March 1972, Pettena gave three performances with his architecture students from the University of Utah, where he was teaching as a guest professor: Clay House, Tumbleweeds Catcher and Red Line. Entitled The Salt Lake Trilogy, this project was envisaged as “a trilogy to be read as a metaphor for the contradictions of the contemporary city” (Gianni Pettena).
In April 1971, the Italian artist and his students gave their first performance, Clay House, during which they covered a middle-class home with wet clay. The obstruction of all the house’s openings resulted in the imprisonment of its inhabitants for several weeks. The clay quickly dried, transforming the house into a “landscape” and causing a “re-naturalization” of the architecture. For Pettena, it was a matter of focusing on his “work with material” through the drying process. The architecture of this house was no longer a large inert object, but a geological crust subject to crumbling and erosion, an evolving material whose appearance became unpredictable. In this intervention, the addition of this material paradoxically engendered an effect of derealization, giving the house an uncertain and ghostly look.