The aim of this lecture is to present the results of a study on the" Building of the Shops with Windows" in Ostia antica and to show how a stratigraphical analysis of the preserved structures can help reconstruct the building and life phases characterizing this parcel of land over the centuries, from the Republic to the Late Antiquity. Thanks to a rigorous methodology, inspired by building archaeology, the walls reveal all the complexity and the richness of the life in this part of the city. In this case, more than seven building phases were identified, and each of them could be relatively well dated, thanks to the analysis of the vertical stratigraphy, the archival record. The analysis of the remaining structures has also allowed to reconstruct different aspects of the building during its life, among which its original aspect and its functioning: number of floors, roofing, water and closing system, wall and floor decoration, relation to the other buildings. In this study, we have tried to show the importance of studying the microcontext in order to understand the macrocontext. In fact, the study of a single parcel of land and its surroundings has provided a series of elements and dates that help reconstruct a broader reality, in this case the urban development of western district of Ostia from the 1st c. BC to the end of the 5th c. AD.