Oecus, the Latinized form of Gr. oikos, house, used by Vitruvius

Vitruvius

Marcus Vitruvius Pollio was a Roman writer, architect and engineer, active in the 1st century BC. He is best known as the author of the multi-volume work De Architectura ....

 for the principal hall

Hall

In architecture, a hall is fundamentally a relatively large space enclosed by a roof and walls. In the Iron Age, a mead hall was such a simple building and was the residence of a lord and his retainers...

 or salon in a Roman house, which was used occasionally as a triclinium

Triclinium

A triclinium is a formal dining room in a Roman building. The word is adopted from the Greek τρικλίνιον, triklinion, from τρι-, tri-, "three", and κλίνη, klinē, a sort of "couch" or rather chaise longue...

 for banquets.

When of great size it became necessary to support its ceiling with columns; thus, according to Vitruvius, the tetrastyle oecus had four columns; in the Corinthian oecus there was a row of columns on each side, virtually therefore dividing the room into nave

Nave

In Romanesque and Gothic Christian abbey, cathedral basilica and church architecture, the nave is the central approach to the high altar, the main body of the church. "Nave" was probably suggested by the keel shape of its vaulting...

 and aisle

Aisle

An aisle is, in general, a space for walking with rows of seats on both sides or with rows of seats on one side and a wall on the other...

s, the former being covered over with a semicircular ceiling. The Egypt

Egypt

Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...

ian oecus had a similar plan, but the aisles were of less height, so that clerestory

Clerestory

Clerestory is an architectural term that historically denoted an upper level of a Roman basilica or of the nave of a Romanesque or Gothic church, the walls of which rise above the rooflines of the lower aisles and are pierced with windows. In modern usage, clerestory refers to any high windows...

 windows were introduced to light the room, which, as Vitruvius states, presents more the appearance of a basilica

Basilica

The Latin word basilica , was originally used to describe a Roman public building, usually located in the forum of a Roman town. Public basilicas began to appear in Hellenistic cities in the 2nd century BC.The term was also applied to buildings used for religious purposes...

than of a triclinium.