Sustainability in the 3D printing of housing and settlements co- design processes.

The current narration of the world's events recalls us, once more, that the phenomenon of migration is one of the ones earmarked to change regularly human geography under the weight of human communities' (re-) placement and (re-)distribution on the territories, repeatedly, due to continuous globally spread "emergency states". Earthquakes, tsunamis, pandemics, poverty, lack of basic need provisions, and wars - with the related humanitarian crisis and consequential refugee migrations - raise their common topic once more: the need for effective answers for emergency housing to this old and never-ending happening. In such conditions, one of the first and urgent issues to answer is the housing emergency, in pair with the need for cheapness and rapidity (in implementations) and flexibility and co- designing (in adaptations). Apart from the relevance of the reasons that drive these global complex movements, it is undoubted there is a matter to consider the effects it is having on the designing codes and their innovation, at all design scales. The actual fourth industrial revolution is widening our potentialities in that. The improvement of the 3D printing tools and supplies, together with the growing opportunities to print even bigger "objects" - until the printing of entire houses fully furnished - is opening interesting new rooms, never thinkable prior. These opportunities mark an innovative track for design, as well as a suitable pathway in case of different emergencies, from natural to human-made ones. Starting by analyzing the current state of the art in 3D printing and a real Pilot case in Italy, this paper aims to show nowadays we are allowed in thinking of cheaper, faster, local-based, flexible, cyclical, and real-time implementable processes, through real sustainable participatory co-designing actions.