Co-presence and co-awareness are key to understanding the dialectics between physical environments and society. As such, they promise to deliver spatial indices for social col-lectivity models, while rendering the social condition in ﬁne relief: e.g. public vs. private (Doxa, 2001). In Space Syntax literature, co-presence and co-awareness have come to de-scribe potential patterns of encounter between individuals as aﬀorded by built settings. Together as “operation concepts”, they establish Hillier’s theoretical concept of ’virtual community’: forms of solidarity aﬀorded by settings (Hillier, 1996).Current socio-spatial descriptions employing co-presence and co-awareness concepts remain inadequate in at least two signiﬁcant respects. First: there exists no distinction between the two concepts possessed of deep conceptual grounding. The two notions are used with substantive overlaps as to render them, if not interchangeable, then practically analogous. So far, deﬁnitions have been empirically derived; which makes gauging their independence as variables a thorny undertaking. Furthermore, some accounts unquestion-ingly imply that co-awareness is a measure derivative from co-presence.Second: while co-presence and co-awareness are necessary designations of virtual com-munity or, generally, social conviviality, they do not suﬃciently cover its dimensions. One may contemplate sister concepts, each with its potential inventory of measures, that co-here a more comprehensive picture of the social life of built environments. More aptly than co-awareness, co-visibility better describes the nuances of visual relations aﬀorded by building settings or gatherings. After Goﬀman’s notion of ‘interdependency of action’ (1983), co-action captures patterns of coordinated action and movement within gatherings. Co-present is also distinct from mere co-extant: bodily juxtapositions in space.This paper posits one conceptual distinction between co-presence and co-awareness, arguing that it straddles the fundamental fault-line Space Syntax attempts to bridge: Structuralism’s impasse between the cognitive realm of rule-making, and the everyday habitus of visceral perceptions and actions (Hillier & Hanson 1984). Simultaneously, I will outline the matrix of conviviality, as a theoretical category within which nest co-presence and co-awareness but also other notions such as co-action and co-visibility - proposing that this matrix constitutes the structure of agency through which the dialectics between physical-environments and society unfold.To demonstrate, I will discuss entries to the Palace of Soviets Competition (Moscow 1931-34) by Corbusier and the avant-garde Soviet Rationalists (Ladovski and ARU: Union of Architect-Urbanists). Frequently, post-revolutionary Soviet design tasks required ac-commodating large crowds and mass activities, where measures of conviviality acquired heightened signiﬁcance as architectural design challenges. Examining the design drawings submitted, I will analyze the spatial propositions they represented, as indicative of how social collectives are visualized by architects.