Certain Roman building types - above all, temples - were remarkably conservative over the centuries. In the late fourth century CE, for example, when the Temple of Saturn in the Roman Forum was reconstructed, it was rebuilt on the same plan and with virtually the same architectural conventions as the 400-year old structure it replaced.

There were, however, several periods of rapid change in Roman prestige building. The great revolution in Roman architecture occurred in the mid- and late first century, when concrete was first used to construct domes and vaults of unprecedented size and grandeur. The pioneers of the concrete revolution were the architects Severus and Celer, who designed a series of startlingly innovative spaces for Nero's colossal Golden House. Within a few decades, soaring concrete vaults were standard in large bath buildings in Rome and major provincial cities. The startling rotunda of the Pantheon and the dazzling eccentricities of Hadrian's Villa are only the most famous products of the new architectural repertoire.

There were also a few eras in Roman history that witnessed the emergence of something approximating a period style. The building boom that swept the provinces in the prosperous second and early third centuries set the stage for the emergence of an Empire-wide monumental style, characterized by extensive use of marble and baroque exuberance in architectural sculpture. Although regional characteristics endured, the mutual imitation of ambitious local elites and the provision of standardized architectural elements from imperially-controlled quarries combined to lend many cities a distinctively second-century "look."

Architectural movements in the modern sense are of course products of capitalist/consumerist trends alien to the ancient world. But in at least some respects, there were real and noticeable trends in Roman architecture.