Roman two-story mansion with two balconies,

Roman houses have a red line at the bottom for aesthetic and functional reasons, often created by using red clay tiles for the lower part of the walls or by applying a red plaster or whitewash to protect the lower parts of the wall from dirt and moisture. This practical use of red-toned materials was also a common visual element in Roman architecture, which often featured decorative plasterwork and painted walls in different colors.