Ancient Roman architecture developed different aspects of Ancient Greek architecture and newer technologies such as the arch and the dome to make a new architectural style. Roman architecture flourished throughout the Empire during the Pax Romana. Its use of new materials, particularly concrete, was a very important feature.
Roman Architecture covers the period from the establishment of the Roman Republic in 509 BC to about the 4th century AD, after which it becomes reclassified as Late Antique or Byzantine architecture. Most of the many surviving examples are from the later period. Roman architectural style continued to influence building in the former empire for many centuries, and the style used in Western Europe beginning about 1000 is calledRomanesque architecture to reflect this dependence on basic Roman forms.
The Ancient Romans were responsible for significant developments in housing and public hygiene, for example their public and private baths and latrines, under-floor heating in the form of the hypocaust, mica glazing (examples in Ostia Antica), and piped hot and cold water (examples in Pompeii and Ostia).

he Roman Architectural Revolution, also known as the Concrete Revolution,[4][5][6] was the widespread use in Roman architecture of the previously little-used architectural forms of the arch, vault, and dome. For the first time in history, their potential was fully exploited in the construction of a wide range of civil engineering structures, public buildings, and military facilities. These included amphitheatres, aqueducts, baths, bridges, circuses, dams, domes,harbours, and temples.
A crucial factor in this development, which saw a trend toward monumental architecture, was the invention of Roman concrete (opus caementicium), which led to the liberation of shapes from the dictates of the traditional materials of stone and brick.[7]

The Romans made fired clay bricks, and the Roman legions, which operated mobile kilns, introduced bricks to many parts of the empire. Roman bricks are often stamped with the mark of the legion that supervised their production. The use of bricks in southern and western Germany, for example, can be traced back to traditions already described by the Roman architect Vitruvius.
Roman brick was almost invariably of a lesser height than modern brick, but was made in a variety of different shapes and sizes.[19] Shapes included square, rectangular, triangular and round, and the largest bricks found have measured over three feet in length.[20] Ancient Roman bricks had a general size of 1½ Roman feet by 1 Roman foot, but common variations up to 15 inches existed. Other brick sizes in Ancient Rome included 24" x 12" x 4", and 15" x 8" x 10". Ancient Roman bricks found in France measured 8" x 8" x 3". The Constantine Basilica in Trier is constructed from Roman bricks 15" square by 1½" thick.[21] There is often little obvious difference (particularly when only fragments survive) between Roman bricks used for walls on the one hand, and tiles used for roofing or flooring on the other, so archaeologists sometimes prefer to employ the generic term ceramic building material (or CBM).
The Romans perfected brick-making during the first century of their empire and used it ubiquitously, in public and private construction alike. The Romans took their brickmaking skills everywhere they went, introducing the craft to the local populations.[21] In the British Isles, the introduction of Roman brick by the ancient Romans was followed by a 600–700 year gap in major brick production.
Roman concrete[edit]
Main article: Roman concrete
Although concrete had been used on a minor scale in Mesopotamia, Roman architects perfected Roman concrete and used it in buildings where it could stand on its own and support a great deal of weight. The first use of concrete by the Romans was in the town of Cosa sometime after 273 BC. Ancient Roman concrete was a mixture of lime mortar, aggregate, pozzolana, water, and stones, and was stronger than previously-used concrete. The ancient builders placed these ingredients in wooden frames where they hardened and bonded to a facing of stones or (more frequently) bricks.
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.
Though most would consider concrete the Roman contribution most relevant to the modern world, the Empire's style of architecture can still be seen throughout Europe and North America in the arches and domes of many governmental and religious buildings

Greek architects provided some of the finest and most distinctive buildings in the entire Ancient World and some of their structures, such as temples, theatres, and stadia, would become staple features of towns and cities from antiquity onwards. In addition, the Greek concern with simplicity, proportion, perspective, and harmony in their buildings would go on to greatly influence architects in theRoman world and provide the foundation for the classical architectural orders which would dominate the western world from the Renaissance to the present day.

MATERIALS
The Greeks certainly had a preference for marble, at least for their public buildings. Initially, though, wood would have been used for not only such basic architectural elements as columns but the entire buildings themselves. Early 8th century BCE temples were so constructed and had thatch roofs. From the late 7th century BCE, temples, in particular, slowly began to be converted into more durable stone edifices; some even had a mix of the two materials. Some scholars have argued that certain decorative features of stone column capitals and elements of the entablature evolved from the skills of the carpenter displayed in more ancient, wooden architectural elements.
The stone of choice was either limestone protected by a layer of marble dust stucco or even better, pure white marble. Also, carved stone was often polished with chamois to provide resistance to water and give a bright finish. The best marble came from Naxos, Paros, and Mt. Pentelicon near Athens.

Greeks
--softer stones like limestone easier to carver
--most buildings above ground
--columns often done in sections and stacked
--sculpture is individual and specifically human in honoring the nude and semi nude form
--stones are large but nothing on the scale of Egyptian structures
--sites often chosen for height, closeness to a view, position of power
--vaulted ceilings like beehive tombs
--statues are of gods and heroes and philosophers--people of political thought. Not so much kings or leaders
--lots of use of post and lintel construction, using columns as posts
--

Egyptians
--worked basalt and granite--some of the hardest stone there is
--lots of tunneling and below ground structures with tubes and holes that defy explanation.
--larger stone monoliths than the Greeks like obelisks and solid stone statues
--carving into the face of a mountain to create a building, like the temple of Hapsetshut and Abu Simbel
--largest structures in the world to include the pyramids
--buildings more likely to revolve around astronomy and constellations
---large burial tombs for royalty and also extensive caves carved like the Valley of the Kings
--extensive carving of hierolglyphics on the sides of buildings and columns.
--sculptures include gods with symbolic animal heads and standardized representations of pharaohs and others.

Ancient Egyptian architecture is the architecture of ancient Egypt, one of the most influential civilizations throughout history, which developed a vast array of diverse structures and great architectural monuments along the Nile, among the largest and most famous of which are theGreat Pyramid of Giza and the Great Sphinx of Giza.