brick-faced tenement
The House Of Diana At Ostia, a fine example of architecture of the mid second century AD. It rose at least four floors, with separate small apartments grouped round a central light-well. The broad shop-openings, the small windows lighting mezzanine floors above them, and the shallow balcony carried on arched corbels, are all characteristic of this building type. The housing of a major commercial city of the high imperial age is best studied at Ostia, largely rebuilt according to new building standards during the second and early third centuries A.D. Here, although some single-storey domus still survived and new kinds of courtyard houses, complete with resplendent marble veneer, were added at a later date, the characteristic type of accommodation was the insula, or apartment block, three, four, or five storeys high. Unlike the domus, this faced outwards, with large windows often opening on to shallow balconies (not always accessible, however, and designed more to shelter the windows beneath than to provide extra space for the tenants). Its great virtue was its flexibility, both in plan and, as a consequence, in the life-style that it offered. It could take the form of a long narrow block, one living-unit in depth; of a rather deeper block, with two sets of living-units arranged back to back; or, where a building plot was particularly deep or neighbouring buildings obstructed the light, of a foursided block round a central court. Within these basic formulae the variations were legion. A favourite treatment of the street front, foreshadowing the architecture of medieval and Renaissance Italy, was a succession of barrel-vaulted shops interspersed with stairways leading straight from the street to the upper storeys. The ground floor of the insula might, alternatively, be divided into two or four more or less identical self-contained flats, entered either directly from the exterior or from an internal dividing corridor. Sometimes, as in the House of the Muses and the House of the Painted Vaults, the whole, or a large part, of the ground floor constituted a single living-unit. In such cases the occupant was perhaps also the owner of the block, and the other occupants his tenants; at the very least he was himself a superior tenant, able to afford space and amenities denied to his upstairs neighbours, many of whom may have had very small apartments and even single rooms. (Boardman, 1986)