Happiness researchers have demonstrated that everyday social interactions lead to greater happiness and well-being. Yet, feelings of loneliness and social isolation are on the rise. Our goal is to address this challenge and promote social interactions among community members by improving the design of physical spaces around them. Harnessing interdisciplinary knowledge from psychology and computer science, we created a model that predicts the frequency of social interactions that occur in physical spaces. Our research is funded by the Robert Wood Johnson Foundation and already has preliminary applications in the real world. For instance, decision makers of an affordable housing project in Calgary utilized our model to choose between competing designs of a more sociable space for their residents. Our approach can potentially provide a scalable solution to help researchers learn how physical spaces shape social interactions and to help decision makers build more sociable spaces.