What defines 'Opus quadratum'?

Opus quadratum refers specifically to a type of construction technique used in Roman architecture that involves using squared or rectangular blocks of stone. This method is characterized by the precise cutting and shaping of stones to create a strong and durable wall. The term itself derives from the Latin words 'opus', meaning work, and 'quadratum', meaning square or rectangular.

The quality of the masonry in opus quadratum not only provided structural integrity but also allowed for a visually appealing, organized appearance in Roman structures. This method was highly favored in monumental architecture, like temples and public buildings, where uniformity and strength were essential.

In contrast, the other options describe different types of construction methods that do not align with the definition of opus quadratum. Walls made of irregular stones, wooden beams, or thatch do not exhibit the same qualities of squared masonry, which is essential to understanding the significance and application of opus quadratum in the context of Roman architectural practices.