So, as the Roman social strategy tended to do, it took the best qualities of the Greek society as its own.  

For small Roman buildings, the Greek style of construction (horizontal and vertical elements only) was used basically with little or no changes. 

Greek builders were commissioned to build many of them because of their great skill.

Roman conquest of the Etruscans yielded the knowledge of the arch and vault.

In combining this new building technology with the Greek style, it allowed the Romans to expand the height and scale of their buildings. (Arches support more weight than do columns).

Romans have also been accredited with the discovery of concrete, which was much quicker and less expensive to use than the huge stones or bricks that were used by the Greeks and Egyptians in their public and private buildings.

The Greek gridiron town arrangement was combined with larger, more complex buildings and town sites to create cities of unprecedented (at the time) size. 

The Romans concentrated on municipal ease in which the luxuries of Rome in the form of running water, public baths, coliseums and public houses, were available to its citizens, both in Rome and in the outlying areas they would conquer. 

The result of this transplanting of the Roman lifestyle in other lands, was the spread of Roman building style and basic social structure.