Question: what was the central feature of a roman townhouse

title: Ancient Roman architecture
text: When the framework was removed , the new wall was very strong , with a rough surface of bricks or stones . This surface could be smoothed and faced with an attractive stucco or thin panels of marble or other coloured stones called revetment . Concrete construction proved to be more flexible and less costly than building solid stone buildings . The materials were readily available and not difficult to transport . The wooden frames could be used more than once , allowing builders to work quickly and efficiently . Concrete is arguably the Roman contribution most relevant to modern architecture .