At Dura-Europos, homes were architecturally adapted across the late 2nd and 3rd c. CE by different religious groups to serve the needs of their communities. Although the Synagogue, Mithraeum, and Christian Building all began as domestic structures and share a similar architectural development, the origins of the latter have received unique attention through its classification as a domus ecclesiae or house church. This (hyper)focus on the structure's past use as a house does not do full justice to the archaeology of the building. Through an analysis of architectural adaptations, including before-and-after 3D reconstructions and daylight simulations, the authors show how the renovations significantly differentiated the Christian Building from its domestic antecedent and from Dura's houses more broadly. This approach is meant to shift attention away from more generalized, translocal, evolutionary models of Christian architectural development to micro-level archaeological analysis that situates structures within the spatial vernacular of their local contexts.