The rise of the latest pandemic made us question the way we build medical infrastructure. This project revolves around the concept of temporality. BioUnits is a hospital, next to the Geneva Bo-tanical Garden, flexible, to extend or shrink to the patients' medical needs during pandemic times. It's composed of 3D-printed insulation units made of chitosan, a natural polymer that comes from crustaceans. Concerning their afterlife, the units can be decomposed, leaving behind a group of permanent buildings that will acquire new functions which will support the botanical garden, as an extension of it on the site.