Medieval masonry techniques and architectural elements in central-eastern Umbria

Abstract

This doctoral thesis aims to investigate historical architectures of Umbria (central Italy) through the methodologies of Architectural Archaeology. The region is rich in medieval and early modern structures: an extraordinary architectural heritage still endangered by negligence by public authorities coupled with frequent seismic crises. This research aims to enhance future conservation plans and policies by documenting the evidence from architectural palimpsests throughout the region.

A second and associated aim is to define the value of architectural typologies as “type-fossils” and sources for economic history. How can building typologies and techniques be used as a source for chronology? Can building solutions and phenomena shed light on economic trends? To answer such questions, the research has taken advantage of methodologies elaborated in the past decades, particularly by the so-called Scuola Ligure in northern Italy. They can be summarised in three main paths: typological studies on architectural elements (chrono-typology), quantitative analyses on the variations of the size of bricks through time (mensio-chronology) and studies on masonry techniques. None of these approaches has ever been applied in Umbria.

The vast dataset required by these methods has been achieved through the selection of approximately 700 buildings from across the region. The structures, from very diverse periods and social contexts, have been examined through photogrammetric documentations, followed by data extraction and analysis.

Chapter 2 discusses the evidence on the merchandise of building materials through medieval and early modern written sources. The analyses indicated the activation of a vast series of production sites (quarries and later kilns) during the Romanesque period. From the 13th century, the production showed an increasing involvement of public authorities (communes), owning main quarries of their territories and issuing regulations. By the 1300s (the century of the late medieval building boom), an increasing amount of written sources testify the establishment of an interconnected network for the merchandising of building materials: partially overlapping town-based districts. The main projects of the late Romanesque or Gothic style initiated such system, which was stabilised by an increasing civil demand. During the late medieval and early modern period, written records document a higher differentiation in building materials. From the mid-15th century, the Renaissance is accompanied by a need for well-selected stones destinated for facings and decorations; on the other hand, there was an increasing urge for reused materials for utilitarian structural components.

Chapter 3 focuses on a particular building material, which is able to provide crucial historical and economic information: bricks. The size of bricks, based on data from 130 structures of known chronology, has shown a growing trend during the late medieval period, followed by a 16th century stagnation and a scattered scenario from 1600. This trend matches the main historical phases of the late medieval and early modern Italian economy. In a period of significant public stimulus and building boom, communes issued standard modules for bricks around 1250-1350. This public pressure resulted in larger products, balancing the higher costs originated from an increasing demand. Besides different ruling authorities, the interconnections between urban markets encouraged a partial homologation of measures. After 1600, the trend downturned due to the first signs of the early-modern economic decline and a decreasing communal supervision. The absence of public interventions in a context of economic crisis, until 19th century industrialisation, resulted in a higher fragmentation.

The typological study (chrono-typology), reserved to architectural elements, has shown the presence of a numerous sequence of chronologically-indicative types from the 1000 samples collected (Chapter 4). More than 170 variants have been identified, providing a list of highly effective type-fossils, often valid for 50 to 100 years range. The resulting catalogue, presented in dataset volume, represents the first systematic classification for doors, windows and loopholes in Umbria.

Directly dated architectural types have also allowed in understanding the dynamics of diffusion of new architectural solutions. This part of the research is set in the field of cultural innovation studies (Chapter 5). The chapter discusses and analyses the evidence on the movements of skilled builders from other Italian states (1100-1800), and their relationship with the local building community. In the second part of the chapter, these dynamics are investigated through architectural evidence. The arrival and enrooting of new types and techniques was mostly due to socio-economic factors, such as the presence of customers and investments. Peripheral areas could receive architectural innovations relatively early, but they were often unable to absorb it for some decades. However, the evidence suggests that it was also affected by the social value attributed to building types (e.g., status symbol vs utilitarian elements). The results of this chapter also underline the importance of micro-contexts for the validity of chrono-typology as a reliable dating method.

Last but not least, the study on masonry techniques has followed two different paths (chapter 6). On the one hand, a classification of main types based on qualitative categories, underlining those provided by a relative chronological significance. Yet again, variations in masonry techniques appeared to be related to major phenomena in the pre-contemporary building economy. For example, the transition to irregular techniques at the apex of the Italian building boom (14th-15th c.), when an increased demand pushed towards changes in the building industry. It has been possible to highlight more than twenty main masonry types introduced in the region in the last two millennia. Several types appear in different periods, evidencing the importance of quantitative analyses in understanding their exact chronology.

This further aspect is examined in the second half of the chapter. It has been possible to observe the evolution of historical masonry through a series of objective indicators, extracted from the 640 masonry samples collected. In doing so, the thesis has discussed masonry as source of evidence in the field of economic history.

Quantitative methods and innovative data visualisation have also been utilised in an attempt to eliminate chronological biases. The thesis has compared a series of case studies to the consistent dataset of masonry techniques to locate them in a definite chronological period. Such objective attempt to find chronologically-indicative parameters and neutral comparative systems, applicable to other regional contexts too, is one of the most innovative contributions of the thesis. The conclusion of the thesis demonstrates how the three methods mentioned above (mensio-chronology, chrono-typology and analyses of masonry techniques) can reconstruct a detailed economic history. Architectures reacted to the trends of the market and, because of the public involvement in building industry, reacted to changes in the administrative setup too. At the same time, architectures represent a source for a wide spectrum of other historical data (e.g., chronology), which makes them vital sources needing active preservation and further explorations.