Pompeii and Herculaneum give us insight not only into the details of home design, interior decoration, and the furnishings and appliances found in the homes of upper middle-class Romans but also the family routines enjoyed by those who dwelt in these homes. The traditional Roman town house, or domus, typically had only one story, but some particularly in Pompeii had a second. Major considerations in its architecture were the mild climate of the Italian peninsula, love of light and fresh air, and of course access to a good water source. In this article we will be dealing with the most common type of town home, the atrium house, the defining feature of which was the large central courtyard. (In a later study we shall be pleased to discuss apartment dwellings in the larger cities.)
This design differed from our modern homes in several ways. For instance, the front of the house verged right on the street with no exterior elaboration. The few windows were usually small and high, allowing light into the interior of the structure while blocking the heat of the sun (figure 1).

Larger window openings would have made the home uncomfortably cool during the winter and unbearably hot in the summer. To modern eyes, the aspect of the home from the street might seem singularly uninviting, even forbidding and fortress-like. In fact the structure was specifically designed to provide a maximum of privacy, while keeping out
the heat, dust, and noise of the street. The ianua, a heavy double-doored front entrance, faced the street and could be both locked and barred. It opened upon a passageway, of which the first part, the vestibulum, might be separated by a light door or curtain from the interior corridor, the fauces.
This led directly into the atrium, whose high roof sloped downward on all sides towards a large, square opening in the center, the compluvium.
Directly beneath the compluvium, an impluvium, a shallow marble basin, collected rainwater, which then drained to a cistern beneath the house. Usually there was a well head in the atrium floor which provided access to the cistern.
Around the perimeter of this spacious, airy, well-shaded courtyard, sparsely furnished with perhaps a table, bench or chest, doorways led to the rooms used by the master's family (fig. 2).

The entrances to these rooms were normally closed with a curtain rather than a door. Adding to the sense of space one felt in this room with its opening to the sky, paucity of furnishings, and plain marble slab floor were the wall paintings often found here (figs. 3, 4 and 5).

Favorite colors ran to red, orange, and blue, while themes featured Greek mythology.
The principal tabulinium (office, salon, or study) normally occupied the end of the atrium farthest from the main entrance. This room, as circumstances required, often served as a place where the tabulae (records) of the family archives and the imagines (portraits) of the ancestors were kept, and it could also be used as a dayroom or an informal dining area.
Your respectful correspondent once had the pleasure of living for two years in a house in Puerto de Santa Maria, a small town on the Bay of Cadiz in southern Spain, whose architectural design philosophy was nearly identical to the ancient Roman houses described herein. I can report from
personal experience, therefore, that the atrium arrangement is most conducive to gracious and comfortable living.

(to be continued)

References:

L. and R. Adkins, "Handbook to Life in Ancient Rome."
M. Grant and R. Kitzinger, Eds., "Civilization of the Ancient
Mediterranean -- Greece and Rome."
Vitruvius, "Ten Books on Architecture."
E. Phinney, Ed., "Cambridge Latin Course -- Unit 1."