The Empire's style of architecture, though no longer used with any great frequency, can still be seen throughout Europe and North America in the arches and domes of many governmental and religious buildings.
The Romans adopted the external language of classical Greek architecture for their own purposes, which were so different from Greek buildings as to create a new architectural style. The two styles are often considered one body of classical architecture. Sometimes that approach is productive, and sometimes it hinders understanding by causing us to judge Roman buildings by Greek standards.
Roman architecture represents a fusion of traditional Greek and Etruscan elements, notably the trabeated orders, with new structural principles based on the development of the arch and of a new building material, concrete.
The Romans achieved originality in building very late in their existence; for the whole of the republican period, Roman architecture was a nearly exact copy of that of Greece, aside from the Etruscan contribution of the arch, and its later three-dimensional counterpart, the dome.
The only two developments of any significance were the Tuscan and Composite orders; the first being a shortened, simplified variant on the Doric order and the Composite being a tall order with the floral decoration of the Corinthian and the scrolls of the Ionic.Innovation started in the first century B.C., with the invention of concrete, a stronger and readily available substitute for stone.
Tile-covered concrete quickly supplanted marble as the primary building material and more daring buildings soon followed, with great pillars supporting broad arches and domes rather than dense lines of columns suspending flat architraves. The freedom of concrete also inspired the colonnade screen, a row of purely decorative columns in front of a load-bearing wall.
In smaller-scale architecture, concrete's strength freed the floor plan from rectangular cells to a more free-flowing environment.On return from campaigns in Greece, the general Sulla returned with what is probably the most well-known element of the early imperial period: the mosaic, a decoration of colorful chips of stone inset into cement.
This tiling method took the empire by storm in the late first century and the second century and in the Roman home joined the well known mural in decorating floors, walls, and grottoes in geometric and pictorial designs.
Though most would consider concrete the Roman contribution most relevant to the modern world, the Empire's style of architecture, though no longer used with any great frequency, can still be seen throughout Europe and North America in the arches and domes of many governmental and religious buildings.