Our reconstruction work on a cistern located on the northern side of the excavation demonstrates our working process. This building had received several phases of archaeological intervention in the past and was subsequently sampled and surveyed by the Portus Project team. In addition dendrochronological data was gathered. A series of computer graphic models were produced as the recording and interpretation of the building has continued. The production of these models facilitated discussion amongst the project team and also provided an immediate means for transmitting the current state of interpretations. Often on an excavation communication between participants is limited by practical, frequently spatial constraints. Construction of models as the excavation continues has helped us to develop an ongoing dialogue about this part of the site, and the site as a whole.