At the end of the 2019-2020 academic year, in the face of the global COVID-19 pandemic, the University of Valladolid (UVa) made the decision to provide safe faceto-face teaching in the following academic year . On 6 July the Governing Council of the UVa approved the Teaching Methodology Document for the 2020-2021 academic year, in line with the document agreed by the four Public Universities of Castilla y León and the Ministry of Education General Criteria for the Adaptation of Teaching during the 2020-2021 Academic Year to Health Requirements (22 June 2020)2 and Preparation of the 2020-2021 academic year (24 July) . One of the priority issues was the definition of criteria for occupancy in teaching spaces, to achieve safe face-to-face teaching, complying with the measures that the health authorities, both national and regional, had laid down to combat COVID-19 . To this end, a Commission was set up, chaired by the Vice-Rector for Infrastructures, with representatives of all the Faculties and Schools and the advice of the Technical Architecture Unit, to create what was called the Digitised Map of Safe Spaces of the University of Valladolid, a totally pioneering action in Spain on this issue . From the first moment, the Higher Technical School of Architecture was considered as a pilot centre, taking the first steps and generating occupancy and circulation systems, which would be extended to the rest of the centres, for which it would serve as a model . The first measure consisted of formulating two occupation parameters in the teaching spaces: on the one hand, the safety distance of 1 .50 m . of separation between the students, and, on the other hand, the maximum occupancy of 3 m2 per person over the entire surface of the space . The second consisted of organising a system of safe itineraries, both in the entrances and exits of the buildings and in the interior routes, as well as in the entrance and exit of the teaching spaces themselves . Finally, the Higher Technical School of Architecture began an exhaustive work in relation to the ventilation conditions in the classrooms . All this, its procedures and its results are detailed in this paper .
