This project is based around myself (student/young professional) and the need for a quality house after graduating, because the current housing demand of affordable high quality housing does not meet the availability. One cause of this problem is the rather old fashioned construction industry that cannot meet the required amount of housing units that have to be built. Therefore more high tech equipment on the construction site is introduced, while also opting for more sustainable materials. These interventions are based in the city center of Rotterdam, on parasitic like empty building plots. By looking at the target group, tiny houses are suited best for this particular case (this target group). A mobile 3D printer is used to print buildings in-situ, with a sustainable construction material called basalt fiber reinforced polylactic acid. This material is made from renewable and natural sources and can be used in a circular material economy, while it can still be separated to its original raw materials. The design of the building is completely parametrically, meaning this procedure can be used for multiple small locations within the city, but can also be applied to other cities. All these interventions (3D printer, Parametrically designed, a new sustainable material, parasitic tiny houses) could possibly help reduce the housing crisis.