Together, the concepts of heterarchy and collective action offer potential explanations for how early state societies may have established high degrees of civic coordination and sophisticated craft industries in absence of exclusionary political strategies or dominant centralised political hierarchies. The Indus civilisation (c.2600-1900 B.C.) appears to have been heterarchical, which raises critical questions about how its infrastructure facilitated collective action. Digital re-visitation of early excavation reports provides a powerful means of re-examining the nuances of the resulting datasets and the old interpretations offered to explain them. In an early report on excavations at Mohenjo-daro, the Indus civilisation’s largest city, Ernest Mackay described a pair of small non-residential structures at a major street intersection as a “hostel” and “office” for the “city fathers.” In this article, Mackay’s interpretation that these structures had a public orientation is tested using a geographical information systems approach (GIS) and 3D models derived from plans and descriptions in his report. In addition to supporting aspects of Mackay’s interpretation, the resulting analysis indicates that Mohenjo-daro’s architecture changed through time, increasingly favouring smaller houses and public structures. Close examination of these small public structures also suggests that they may have at times been part of a single complex.