This paper seeks to establish a chiasmus between notions of site as something produced and buildings as sites of production. The focus is upon Herzog and De Meuron's Schaulager in Basel, cast from and on the ground of its site, and Peter Zumthor's Bruder Klaus Field Chapel at Wachendorf, cast on local trees in hand-mixed aggregate from the site, trodden in layers by locals. Both buildings involve moulding, where a tangible transposition of site to building is produced by imprint and material transformation.

These polarities of site and production, form and matter, trace and transformation are deployed as a heuristic device to unfurl a space for thinking possibilities especially those raised by Gilbert Simondon's distinction between Plato's and Aristotle's concepts of the genesis of things in making- ‘individuation’. The buildings' materials and the mud of the fields, masses worked by hand and foot, take form by not quite taking form; this is the potential of the plastic. The act of making is examined here in imprints and traces through their capacity for signification and, in acts of production, for revealing processes and potentialities remaining after actualisation. Interaction between site and production is found to achieve poetic quality through localisation of materials.