Abstract This master’s thesis explores the houses on the Greek island of Delos in the Late Hellenistic period, second and first centuries BC, when Delos was an important port city in the Mediterranean trade at a time when the Roman Empire expanded into the Eastern Mediterranean. The author uses quantitative analytical methods from space syntax and architectural energetics studies to analyse the spatial structure, architecture and decoration of a sample of Delian houses. Additionally, the author uses a theoretical framework based on central scholars such as Michel Foucault, Pierre Bourdieu and Amos Rapoport to shed light on the relationship between humans and the built environment. This thesis explores how people and the built environment structure each other, and which factors influenced the forms of houses in a cosmopolitan society, where people from the Western and Eastern Mediterranean settled and lived. The research question being whether social, economic, cultural or ethnic backgrounds of the inhabitants were the determining factors for shaping the houses. Based on the analytical results, the author concludes that the Delian houses are products of several factors such as topography, land loot and building history. Concerning the inhabitants, socioeconomic and cultural factors appear to be the main determinants for house form. Inhabitants strived for social status and prestige and participation in elite culture and cultural koine. Monumentalising architectural elements such as peristyles, mosaics, wall paintings and statues have been used to showcase status and what Amos Rapoport calls costly signalling and Bruce Trigger thermodynamic energy use in which energy in the form of labour and resources are used to demonstrate, maintain and win power and status in society. Under the category of ethnic markers falls liturgical paintings on house facades and altars that were part of festivals. Other potential markers include more sporadic finds, such as apotropaic symbols, sculptures, portraits and inscriptions that are limited to contexts involving cult practices of foreign gods and cults practised on Delos by inhabitants and visitors or promoting patrons and benefactors. Concluding that Delos represents a broader phenomenon of the Hellenistic and Roman period in which the domestic dwelling was an essential social and political arena, into which the wealthy elite and sub-elite invested resources in architecture and decoration.