It's now well appreciated that social determinants of health are the strongest predictors of our health and well-being. A good argument could be made that housing is at the top of the pyramid of these determinants. And, surprisingly, housing is also the social determinant that could rapidly turn on a dime-that is, with sufficient political will, creating access to housing could be radically expanded in short order. (Unfortunately, of course, it's true one can also become suddenly homeless, since few protections exist in policy or capitalist economies to prevent it). That alone sets it apart from social factors such as education and racism-conditions that take a long time to change. In contrast to long-term interventions (education) or culturally stubborn and historically rooted problems (racism), housing is rapidly malleable. In this article, we describe the social condition of homelessness in two settings, comparing and contrasting the concepts, causes, and consequences, along with how people are mobilizing to challenge the conditions that create their housing insecurity. As we review the factors that create housing conditions in each setting, we propose some universal international principles for a new approach to the human right of decent and secure housing.