This article develops Sensory–Political Topography (SPT) as a normative–analytic framework for diagnosing and improving micro-public realms. SPT bridges the dominant access and service-provision agenda in social-infrastructure research with theatre/space debates on staging, thresholds, and atmospheres, and conceptualises the sensory–spatial conditions of publicness at the scale of the venue as four parameters: public visibility, sensory commonality, embodied participation, and spatial permeability. Each parameter is operationalised through a practical rubric with clear definitions, observable indicators (proxy measures), evaluation criteria, and design/operational levers. Methodologically, the study is theory-driven: secondary materials (time-stamped vignettes; spatial readings of plans and photographs) are used to conduct a single-case stress test on an independent venue in Istanbul. The analysis shows how threshold ecologies and staging arrangements render actions publicly visible while assembling a field of sensory commonality, and how these configurations act as effective levers in helping to sustain that field. The contribution is twofold: (i) an operational theory of micro-publicness that links atmospheric conditions to concrete spatial and organisational choices; and (ii) a transferable assessment-and-intervention rubric to inform the design and evaluation of social infrastructure across venues such as libraries, community centres, and clinics. Limitations include the absence of new participant data and the single-site scope; future work should test SPT across multiple settings with mixed methods.