Threshold conditions range from physical, to social, to the phenomenological. Physical thresholds demarcate the spaces in-between and at the periphery. They are often adjunct to particular scapes, spaces, rooms, buildings, cities and nations. How is the space in-between maintained across scales? How are peripheries and limits defined or distinguished? Thresholds also demarcate changing physical and social conditions or states. Social thresholds are observed at the scale of the individual and at the scale of society in ceremonies and rituals that demarcate shifting life phases. The thresholds of social change and physical state change may be interpreted as ruptures. Phenomenological thresholds do not rely upon physical or social forms for meaning; they directly engage the senses. The many definitions of thresholds span from the physical demarcation of boundaries to potent architectural tropes, thresholds and reveal cultural approaches to space and construction. By focusing on the design of in-between and transitional spaces the studio explores the valuing and design of spatial distinctions, transitions and spatial limits for transformative potentials. The studio engages architectural design through a series of interrelated architectural design problems that are delivered sequentially in a one-page program brief in which the scale, and length of time spent on the challenges vary. Moving through the series of architectural design problems, each student develops an individual formal language and an evolving threshold thesis that culminates in a threshold building.