Houses in Byzantium stood inside the city walls, organized in blocks on a network of main and secondary streets. Building land in cities decreased over time, to the point where houses were right next to one another, with a dividing wall in between. In Late Byzantium houses were built wherever suitable land was available.
 
In the first centuries, houses in the big cities of the empire were either built on one storey around a central courtyard, or had two or more floors divided into apartments for several families. There were also well built houses owned by the rich, which stood out from the rest. Most of what we know about house building techniques comes from written texts and archaeological excavations: the commonest materials were stone, brick and wood, held together by sand and lime mortar. Mud was used in place of sand for more modest buildings, but for neater looking ones pieces of broken tile were added to the mud. This made the mortar more resistant, while at the same time the tiny pieces of tile acted as insulation. Wood was used for roofs, hayats and projecting sections - in Late Byzantine Constantinople there were even houses several storeys high built entirely of wood. Unfortunately only a few examples of secular architecture have survived. This is partly because of the low grade building materials used, and also because materials or even entire parts of old houses were reused in newer constructions.

The fact that cities were so densely built forced the state to make building and town planning laws that regulated house construction and rules of good neighbourliness. This was to make houses look good and ensure they were hygienic, with plenty of sunlight and fresh air. For example, Emperor Zenon made a law specifying how many floors a house could have, how the balconies and staircases could be built, and how far apart houses should be (at least 12 feet, otherwise they could not have windows on the side facing the neighbouring house). A new law made by Justinian for Constantinople ordered that no house should be so tall that it prevented light from reaching the neighbouring one or blocked its view to the sea. Wealthy homeowners were required to repair their house fronts and decorate them with marble, so that they offered “true beauty for the city and delight to passers-by". Lastly, the Strategikon by Kekaumenos recommended that for security reasons homes should not be built directly against the walls, though this prohibition was rarely applied.

On the ground floor of Middle Byzantine houses we find features that would be better suited to a farmhouse: large jars for olive oil, wine and grain show that they were used as storage areas. There was also equipment, as in the case of a corn mill mentioned in a description of an 11th century house in Constantinople.

We do not know whether wealthy neighbourhoods were separated from those of the poor. Mystras is one example of a city where the mansions were concentrated in the upper town, near the palaces of the Despots. Something similar is also seen in Adrianople, where the nobles lived in the upper town, between the citadel and the middle wall. It may be that the wall built in several cities in mid-Byzantine times divided them into neighbourhoods, depending on the social status of those living there.

Byzantine cities also had minorities (Jews, for example), who lived in separate neighbourhoods, and foreign merchants (such as Italians), who often lived outside the city walls. In the case of the Jewish population this habit became weaker over the years, though the tendency to live in isolation did remain.