The Economics of Construction in Imperial Roman Architecture

16 June 2021

This lecture explores the economics of construction in the Roman world, with a particular focus on the advantages of a strong form of mortared rubble usually – but rather erroneously – called concrete. Used increasingly in the city of Rome, this construction technique did not appear in isolation, but as a response to the demands of the short-term magistrates of the Republic looking enhance their socio-political prestige, and then of the Roman emperors looking to emphasise their legitimacy and power, all requiring always larger, more complex and novel structures, built quickly but economically, to fulfil their needs. It was also a key factor in the expansion of the city and the constant renewal of the urban fabric necessitated by the twin poles of political will and natural disaster. In the almost total absence of ancient building records or costs for the city of Rome, the scale and nature of the economic factors involved in creating the eternal city have to be estimated using architectural energetics based largely on 19th century building manuals and the ethnography of traditional building practices, many of which scarcely changed until the start of the 20th century. This provides a window onto the range of economic advantages of mortared rubble construction over traditional ashlar, in terms of the supply of materials, the redeployment of building debris, the balance of unskilled or semi-skilled labour in respect to highly skilled workers, and the speed of construction. Finally, the paper will briefly consider the concomitant development of window glass, which added environmental to the economic advantages of mortared rubble construction, while radically changing the face of ancient architecture.

Janet DeLaine began her academic career at the University of Adelaide, South Australia, where she studied Civil Engineering before turning to Classical Archaeology. Her career took her to Oxford via the British School at Rome, where she is currently Emeritus Fellow at Wolfson College. Her research focuses on the built environment of the Roman world, in particular the Roman building industry, Roman baths, and the urban development of Rome’s port city of Ostia. Author of many articles, she has just completed a short introduction to Roman architecture for the OUP History of Art Series. Her publication The Baths of Caracalla in Rome: a study in the design, construction and economics of large-scale building projects in imperial Rome (1997), won the Archaeological Institute of America’s James R. Wiseman Award for the most important work in archaeology for 1998, and has been fundamental in the development of the archaeology of construction as a new discipline within the field of classical archaeology. She is a Fellow of the Society of Antiquaries and a Corresponding member of the Archaeological Institute of America, and has lectured widely in Europe, North America and Japan.

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The event will take place at 6pm on Wednesday 16th June.