Determining the internal layout of archaeological structures and their uses has always been challenging, particularly in timber-framed or earthen-walled buildings where doorways and divisions are difficult to trace. In temperate conditions, soil-formation processes may hold the key to understanding how buildings were used. The abandoned Roman town of Silchester, UK, provides a case study for testing a new approach that combines experimental archaeology and micromorphology. The results show that this technique can provide clarity to previously uncertain features of urban architecture.