What Rome forgot: structure before concrete

For my final-year dissertation I followed a long-standing interest in architectural history into the structural technologies of the Roman world. Through hand-drawn axonometric sketches, I compared the building techniques and materials of private dwellings, baths and aqueducts built in 2nd-century AD metropolitan Rome with their counterparts in the Roman provinces of Greece and Asia Minor (present-day Turkey).

The popular story is that concrete was one of Rome's great exports, radiating out from the capital. The evidence tells a more interesting tale. In many provinces concrete was an undesirable choice for local builders: every region had its own geology, constraints and abundant local materials, and these shaped building techniques that were more efficient for that place than imported Roman concrete would have been.

• Asia Minor: a rubble-masonry core faced with ashlar cut from locally abundant quarry stone.
• Roman Greece: a rubble core faced with brick.
• Italy: a Roman-concrete core faced with brick — opus testaceum.

The lesson has aged well, and it underpins how I approach sustainable design today: material choices should follow place. What is local, low-carbon and appropriate to a specific site will almost always outperform a default specification imported from somewhere else.