8 Innovations of Roman Architecture

Roman buildings and monuments still stand in many of our cities and towns, some structures still in use today.

How did the Romans, building two millennia ago with nothing but human muscle and animal power, leave such a lasting legacy?

Frigidarium of Baths of Diocletian, today Santa Maria degli Angeli

The Frigidarium of Diolcletian’s Baths.
Photo by Giovanni Dall’Orto via Wikimedia Commons.

The Romans built on what they knew from the Ancient Greeks. The two styles are together called Classical Architecture and their principles are still used by modern architects.

The Parthenon in Athens

The Parthenon In Athens. The Romans took Ancient Greek principles and built on them.

From the 18th century, Neoclassical architects deliberately copied ancient buildings with regular, plain, symmetrical designs with lots of columns and arches, often using white plaster or stucco as a finish. Modern buildings built in this style are described as New Classical.

1. The Arch and the Vault

The Romans did not invent but did master both the arch and vault, bringing a new dimension to their buildings that the Greeks did not have.

Arches can carry much more weight than straight beams, allowing longer distances to be spanned without supporting columns. The Romans realised that arches didn’t have to be full semi-circles, allowing them to build their long bridges. Stacks of arches allowed them to build higher spans, best seen in some of their spectacular aqueducts.

Vaults take the arches strengths and apply them in three dimensions. Vaulted roofs were a spectacular innovation. The widest vaulted Roman roof was the 100 foot-wide roof over the throne room in Diocletian’s palace.

The Interior of the Pantheon by Panini

An 18th century painting of the dome of the Pantheon.

2. Domes

Domes use similar principles of circular geometry to cover large areas with no internal support.

The oldest surviving dome in Rome was in the Emperor Nero’s Golden House, built around 64 AD. It was 13 metres in diameter.

Domes became an important and prestigious feature of public buildings, particularly baths. By the 2nd century, The Pantheon was completed under Emperor Hadrian, it is still the largest unsupported concrete dome in the world.

3. Concrete

As well as mastering and refining Ancient Greek geometrical learning, the Romans had their own wonder material. Concrete freed the Romans from building only with carved stone or wood.

Roman concrete was behind the Roman Architectural Revolution of the late Republic (around 1st century BC), the first time in history that buildings were built with regard to more than the simple practicalities of enclosing space and supporting a roof over it. Buildings could become beautiful in structure as well as decoration.

The Roman material is very similar to the Portland cement that we use today. A dry aggregate (perhaps rubble) was mixed with a mortar that would take in water and harden. The Romans perfected a range of concretes for different purposes, even building under water.

4. Domestic Architecture

The island in Emperor Hadrian's villa at Tivoli.

Hadrian’s villa boasted an island in a domed room where the Emperor could escape the stresses of government.

Most of Rome’s citizens lived in simple structures, even blocks of flats. The rich though enjoyed villas, which were country estates in which to escape the heat and crowds of a Roman summer.

Cicero (106 – 43 BC), the great politician and philosopher, owned seven. The Emperor Hadrian’s villa at Tivoli consisted of more than 30 buildings with gardens, baths, a theatre, temples and libraries. Hadrian even had a complete small home on an indoor island with drawbridges that could be pulled up. Tunnels allowed servants to move around without disturbing their masters.

Most villas had an atrium – an enclosed open space – and three separate areas for owners and slave accommodation and storage. Many had baths, plumbing and drains and hypocaust under-floor central heating. Mosaics decorated floors and murals walls.

5. Public Buildings

Great public structures were built to provide entertainment, to instil civic pride, to worship in and to show the power and generosity of the rich and powerful. Rome was full of them, but wherever the Empire spread, so did magnificent public buildings. Julius Caesar was a particularly flamboyant public builder, and he attempted to make Rome surpass Alexandria as the Mediterranean’s greatest city, adding major public works such as the Forum Julium and the Saepta Julia.

6. The Colosseum

Potoraph of the Colosseum in Rome at night.

The Colosseum in Rome. Photo by Diliff via Wikimedia Commons.

Still one of the iconic sights of Rome today, the Colosseum was a massive stadium that could house between 50,000 and 80,000 spectators. It was ordered built by Emperor Vespasian around 70 – 72 AD, on the site of Nero’s personal palace.

Like many Roman buildings, it was built with the spoils of war and to celebrate victory, this time in the Great Jewish Revolt. It is in four levels, and was completed in 80 AD after Vespasian’s death.

It was the model for similar celebratory amphitheatre throughout the Empire.

7. Aqueducts

Photograph of the Ancient Roman aqueduct near Nimes, now the Pont du Gard.

The Pont du Gard near Nimes. Photo by Benh Lieu Song via Wikimedia.

Romans were able to live in large cities because they knew how to transport water for drinking, public baths and sewerage systems.

The first aqueduct, the Aqua Appia, was built in 312 BC in Rome. It was 16.4 km long and supplied 75,537 cubic metres of water a day, flowing down a total 10-metre drop.

The tallest aqueduct still standing is the Pont du Gard bridge in France. Part of a 50km water delivery system, the bridge itself is 48.8 m high with a 1 in 3,000 downward gradient, an extraordinary achievement with ancient technology. It is estimated the system carried 200,000 m3 a day to the city of Nimes.

8. Triumphal Arches

The Arch of Constantine in Rome.

The Arch of Constantine was built to celebrate the commemorate Emperor’s defeat of Maxentius at the Battle of Milvian Bridge. Photo by David Jones via Wikimedia.

The Romans celebrated their military triumphs and other achievements by building gigantic arches over their roads.

The Roman’s mastery of the arch may have given this simple shape a special significance to them. Early examples were being built by 196 BC when Lucius Steritinus put up two to celebrate Spanish victories.

After Augustus limited such displays to emperors only, the men at the top were in an ongoing competition to build the most magnificent. They spread throughout the Empire, with 36 in Rome alone by the fourth century.

The largest surviving arch is the Arch of Constantine, 21 m high in total with one arch of 11.5 m.

Colin Ricketts studied history at the University of Birmingham, graduating in 1992. He's a qualified librarian, a former journalist and currently a freelance writer and editor.