The Economics of Roman Construction in Bracara Augusta (Braga, Portugal): Building Stone Identification and Working Costs

Bracara Augusta (Braga, Portugal), one of the most important cities of the NW Iberian Peninsula, was founded by the emperor Augustus approximately between the years 16/15 BC. Throughout the Roman period, it has undergone various monumentalisation programmes according to its status, the first one as a convent capital and a later one as a provincial capital. The investigation of the economic cost of construction in the ancient world allows us to understand Roman architecture and the society of builders, both from economic and social perspectives. In recent years, based on the works of Janet DeLaine and Paolo Barresi, despite the large number of variables and the difficulty of quantifying them, a calculation methodology has been developed to approximate the cost of architecture, based on the information contained in two main documents: the Diocletian’s Edict of Prices (301 AD) and the nineteenth-century architecture and engineering manuals summarised by Pegoretti. Our goal is to understand part of the construction process of Roman architecture in the NW Iberian Peninsula, considering the cost of raw materials, namely stone, and the labour required in its preparation and utilisation. In this study, we present a cost proposal associated with the monumentalisation of two of the city’s important buildings: the forum’s large buildings and the theatre. The construction of the city was made fundamentally using local stone, from different quarries, endowing it with notable buildings and requiring a strong contribution from the local elites.