Proceedings of the 13 th Space Syntax Symposium Domestic decryption: A longitudinal configurational analysis of hierarchy in semi-detached houses 1 !"# Domestic decryption A longitudinal configurational analysis of social hierarchy in semi-detached houses !"#$% ’()*!+, -$%. /01"0()0( (%.2!)1."+ -0) "#! 3)!$".2! $)"1 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !"#$%!&$ The architecture of the dwelling is the closest representation of societal behaviours and ideals. An example of such behaviour is social hierarchy which this paper considers as an intrinsic value of the spatial configuration of the domestic space, responsible for mediating everyday interactions between inhabitants and between inhabitants and visitors. By adopting Hiller's and Hanson’s configurational approach to space (1984), this paper examines the evolution of the English semi-detached housing typology to interpret and visualise changes in societal ideals as well as how these have manifested in the functioning and arrangement of interior spaces within this typology over the period of a century (1850-1950). While considering the wider political, technological and architectural context of the time, the study seeks to provide a deeper understanding of the social implications of historical architectural decisions. Such knowledge can be useful for architects and planners involved in the design of houses in order to accommodate changing family structures and living habits in the future. The use of methods and tools from space syntax theory provides evidence of the effect of the configuration of a house plan and its individual spaces, their use and social meaning. Five case study plans, each representing a different historical moment in the evolution of semi-detached typology, are selected for the comparative analysis. The plans are used to produce scans which are examined from two perspectives - that of the occupant and of the visitor - in order to determine hierarchical patterns across different spaces and functions over time. The main analytical tool used in this paper is Isovist_App (version 2.4) developed by McElhinney (2020). The software analyses the five plans, measuring their values of Integration, Visibility, Mean Metric Depth and Visual Control. The produced heat maps illustrate the probable experience of navigating through the building and can be compared both visually and numerically. Besides the