Roman architecture primarily followed which design feature of the Greeks?

Roman architecture indeed drew heavily from Greek design principles, especially in the use of architectural details and the incorporation of features like the portico. The Greeks established a standard that included columns and pediments, which the Romans adopted and adapted in their own buildings. This influence is evident in structures such as temples, where the façade and detailing echo the Greek style while also showcasing the Romans' flair for expansion and adaptation.

The emphasis on the portico—a roofed space supported by columns at the front of a building—was particularly significant, as it not only served aesthetic purposes but also provided a functional area for gatherings and rituals. The inclusion of these decorative elements became a hallmark of Roman architecture, allowing it to merge grandeur with practicality.

While Romans did innovate with materials like concrete and structural elements such as the arch, the primary design feature that they followed from the Greeks was rooted in the specifics of architectural detailing, particularly the portico, which remained an essential component of their monumental buildings.