The hospital in Puyo – a city in Ecuador, at the gates to the Amazon – is the first executed example of a parametric system of health facilities designed in such a way that they can be adapted to different contexts and built with local techniques very quickly, in response to emergency situations. The ‘parametric hospital’ is the result of the need for a single model that can address a whole set of matters: layout, location of corridors in accordance with use, the measurements of the scheme and sheds, the modules of the facade, the roads and the hierarchy of accessways, the arrangement of MEP installations, and provision for future expansions. The complex carried out in Puyo comprises 21 pavilions with sloping roofs fit for the rainy climate of the region. The pavilions open to longitudinal courtyards and are traversed by two corridors, one technical and the other public. Such an organization ensures that all the premises of the hospital benefit from good natural lighting and ventilation.