Roman architecture was unlike anything that had come before. The Persians, Egyptians, Greeks and Etruscans all had monumental architecture. The grandeur of their buildings, though, was largely external. Buildings were designed to be impressive when viewed from outside because their architects all had to rely on building in a post-and-lintel system, which means that they used two upright posts, like columns, with a horizontal block, known as a lintel, laid flat across the top. A good example is this ancient Greek Temple in Paestum, Italy.
Roman architecture differed fundamentally from this tradition because of the discovery, experimentation and exploitation of concrete, arches and vaulting (a good example of this is the Pantheon, c. 125 C.E.). Thanks to these innovations, from the first century C.E. Romans were able to create interior spaces that had previously been unheard of. Romans became increasingly concerned with shaping interior space rather than filling it with structural supports. As a result, the inside of Roman buildings were as impressive as their exteriors.
Materials, Methods and Innovations
Long before concrete made its appearance on the building scene in Rome, the Romans utilized a volcanic stone native to Italy called tufa to construct their buildings. Although tufa never went out of use, travertine began to be utilized in the late 2nd century B.C.E. because it was more durable. Also, its off-white color made it an acceptable substitute for marble.
Marble was slow to catch on in Rome during the Republican period since it was seen as an extravagance, but after the reign of Augustus (31 B.C.E. - 14 C.E.), marble became quite fashionable. Augustus had famously claimed in his funerary inscription, known as the Res Gestae, that he “found Rome a city of brick and left it a city of marble” referring to his ambitious building campaigns.
Roman concrete, was developed early in the 2nd c. BCE. The use of mortar as a bonding agent in ashlar masonry wasn’t new in the ancient world; mortar was a combination of sand, lime and water in proper proportions. The major contribution the Romans made to the mortar recipe was the introduction of volcanic Italian sand (also known as “pozzolana”). The Roman builders who used pozzolana rather than ordinary sand noticed that their mortar was incredibly strong and durable. It also had the ability to set underwater.
We don’t know much about Roman architects. Few individual architects are known to us because the dedicatory inscriptions, which appear on finished buildings, usually commemorated the person who commissioned and paid for the structure. We do know that architects came from all walks of life, from freedmen all the way up to the Emperor Hadrian, and they were responsible for all aspects of building on a project. The architect would design the building and act as engineer; he would serve as contractor and supervisor and would attempt to keep the project within budget.
Roman cities were typically focused on the forum (a large open plaza, surrounded by important buildings), which was the civic, religious and economic heart of the city. It was in the city’s forum that major temples (such as a Capitoline temple, dedicated to Jupiter, Juno and Minerva) were located, as well as other important shrines. Also useful in the forum plan were the basilica (a law court), and other official meeting places for the town council, such as a curia building. Quite often the city’s meat, fish and vegetable markets sprang up around the bustling forum. Surrounding the forum, lining the city’s streets, framing gateways, and marking crossings stood the connective architecture of the city: the porticoes, colonnades, arches and fountains that beautified a Roman city and welcomed weary travelers to town. Pompeii, Italy is an excellent example of a city with a well preserved forum.
Republican Roman architecture was influenced by the Etruscans who were the early kings of Rome; the Etruscans were in turn influenced by Greek architecture. The Temple of Jupiter on the Capitoline Hill in Rome, begun in the late 6th century B.C.E., bears all the hallmarks of Etruscan architecture. The porch is very deep and the visitor is meant to approach from only one access point, rather than walk all the way around, as was common in Greek temples. Also, the presence of three cellas, or cult rooms, was also unique. The Temple of Jupiter would remain influential in temple design for much of the Republican period.
Emperor Nero began building his infamous Domus Aurea, or Golden House, after a great fire swept through Rome in 64 C.E. and destroyed much of the downtown area. The destruction allowed Nero to take over valuable real estate for his own building project; a vast new villa. Although the choice was not in the public interest, Nero’s desire to live in grand fashion did spur on the architectural revolution in Rome. The architects, Severus and Celer, are known (thanks to the Roman historian Tacitus), and they built a grand palace, complete with courtyards, dining rooms, colonnades and fountains. They also used concrete extensively, including barrel vaults and domes throughout the complex. What makes the Golden House unique in Roman architecture is that Severus and Celer were using concrete in new and exciting ways; rather than utilizing the material for just its structural purposes, the architects began to experiment with concrete in aesthetic modes, for instance, to make expansive domed spaces.
Article source: https://www.khanacademy.org/humanities/ancient-art-civilizations/roman/beginners-guide-rome/a/roman-architecture