Thematic sessions Thematic session: Building maintenance in ancient times (up to the early modern period) Thematic session: Architects and bureaucrats: Centralised governments and the administrative pre-conditions of building before 1750 Thematic session: Historic precast concrete Thematic session: Early thin shells - players, impulses, and effects Thematic session: Modern 'comfort' in colonial / postcolonial settings beyond the 'centre / periphery' framework Thematic session: Transnational exchange in the construction worlds of nineteenth and twentieth century Asia: The diffusion of materials and processes in the Global South Open sessions