The so-called Casette Tipo (”model houses”) belonged to a construction project involving the creation of serialized apartments, installed within symmetrical rectangular blocks of buildings. Each block had two apartments on the ground floor; the presence of external staircases suggests the existence of other independent apartments on the upper floors. The residences on the ground floor had a corridor off which opened both the cubicula (bedrooms) and the living rooms; the arrangement was completed by kitchens and latrines. These apartments were probably built for the city’s middle class during the Trajanic period (around AD 110), when Ostia was expanding following the construction of the new seaport, today located in Fiumicino.