Philemon is an architect, social activist, and co-founder of Entremise, a non-profit organization that focuses its work on developing Transitory Urbanism (TU) strategies related to the use of vacant buildings in the city of Montréal. Together with his team, Philémon promotes TU as a way to transform underused spaces into assets for more equitable and sustainable urban futures. At the heart of Entremise and Philémon’s social enterprise is the search for permanence of occupation through TU, especially when it comes to communities whose access to the urban space is limited. They have been involved in successfully occupying many vacant spaces in the city of Montréal; Projet Young, Entremise’s first project, was able to secure space for twenty organizations while the warehouse space had been left vacant while awaiting demolition. Currently, Philémon works on a similar project involving the preservation and the repurposing of the Cité-des-Hospitalières, an iconic historical site in the city that used to be a hospital and a convent, and that is now vacant. In June 2021, public consultations were held in order to determine the collective use of this space. In short, Philmon’s work contributes to our understanding of the interplay between time and space use in an urban setting. If emptiness is seen as an opportunity for creative ways of appropriating the urban space, transitory presence allows people to experiment with spatiality and have a chance to leave their mark on the landscape.