A fusion of architecture and media technology, video-mediated spaces facilitate collaborative practices across spatial extensions. This paper contributes an architectural perspective on presence design, exploring its potential to create architectural extensions that facilitate knowledge-sharing and remote presence. With the example of a mediated therapist, taken from the author's design-led research (Gullström 2010), the paper illustrates spatial design concepts (e.g. mediated gaze, spatial montage, shared mediated space), which, unaddressed, may be said to impose friction, and thus impact negatively on the experience of witnessed mediated presence (Nevejan 2007). Mediated presence cannot be ensured by design, however, by acknowledging that certain features are related to spatial design, a presence designer can monitor them and, in effect, seek to reduce the 'design friction' that otherwise may inhibit e.g. trust and knowledge-sharing. It concludes that a presence-in-person paradigm prevails in our society, founded on the expectations of trust and knowledge-sharing between individuals, and hereby addresses the contribution from presence design to architectural practice -as well as the reciprocal contribution from architecture to presence design -given that mediated spaces currently provide viable alternatives for meetings and interactions, hence with a fundamental impact on all human practices.