The building trades – clamped between architects and the built environment – have much to contribute to urban historiography. Despite the broad consensus amongst historians on the importance of the industry in the early modern urban economy, our understanding of the relations of production in this sector is still limited. Taking the city of Brussels from the late seventeenth to the late eighteenth centuries as a case-study, this project aims to gain insight into the entrepreneurial structures and labour relations in the building trades during the early modern period. It will yield new perspectives on current debates in guild historiography, as it moves away from an institutional approach and considers guilds as nodal points of social relations. This requires a methodology that brings into view the ways in which guilds generated a range of opportunities that benefited specific groups in specific ways. While existing studies are primarily committed to the public building market, this project proposes an integrative approach that also includes semi-public and private markets in order to understand if and how different market segments provided distinct opportunities to certain entrepreneurs and craftsmen, while excluding others. By establishing the interactions between market differentiation, social networks and economic strategies, this project will provide a significant contribution to the history of entrepreneurship, guild history and urban development.