With a strict urban growth boundary in place, a temperate climate, and a growing population, Portland, Oregon offers unique opportunities to experiment with high density infill housing models. The 4424 North Mississippi project explores a basic model of high occupancy habitation, but inverts it, to examine more complex notions of blurring interior environments. The project poses a simple question: can a double loaded housing building provide cross ventilation for the units, thereby reducing the demands for mechanical ventilation and conditioning. The site is very compact with a 12’ grade change, but provides the unique condition of a full north frontage at the sweep of a major Portland district street. Just to the north, the site is buffered by a small community open space/garden, to the south, the site neighbors the landmark N Mississippi neighborhood and a major commercial street. This structure outlines a new strategy for creating livability and community by redefining a seemingly exhausted housing typology. By re-examining the basic organizational tenants, new strategies are revealed.