Nero might have been crazy, but architecture produced under his reign exposes a different side to this mad emperor.
The Architectural Revolution of Rome
The Roman Empire underwent an architectural revolution after the fire of AD 64. This fire, which destroyed much of Rome, exposed the weakness of prior Roman construction. Nero, who was emperor during this incident, took the opportunity to build his Domus Aurea (Golden House) over part of the city that was destroyed. The Domus Aurea was the predecessor of architectural advances that would follow in years to come.
The Domus Aurea
Nero’s Golden house covered 125 acres. It occupied a large area of the Palatine Hill, and parts of the Caelian and Esquiline Hills. The estate consisted of a large park area, vineyards and an artificial lake. The architects of the building were Severus and Celer, who were asked by Nero to build this complex. The only well preserved section standing is the Esquiline Wing, which contained bedrooms, suites, dining rooms, courtyards and a nymphaeum. Most important, it also contained a octagonal room which will be further discussed.
The Domus Aurea itself was built of brick-faced concrete. The use and refinement of concrete was revolutionary. Nero chose this method in order to construct his complex quickly, but he also chose it for its building potential. Brick-faced concrete became popular after the fire of AD 64. It was inexpensive and easy to prepare. It also allowed the architect to experiment in the use of domes and vaulted structures, which can be seen in the Domus Aurea. The Golden House was never completed though, due to Nero’s suicide in AD 68.
The Equiline Wing
As mentioned above, the most important aspect of the Equiline Wing is the octagonal room that sits at the eastern end of the complex. This room is revolutionary due to its use of vaulting. The vault itself derives from the arch. Instead of a post and lintel system consisting of horizontal and vertical planes, the arch is a self-sustaining structure. Two main vault types are the barrel vault and the groin vault. A barrel vault comprises of several arches and is cylindrical in shape, while the groin vault consists of two barrel vaults that intersect at right angles. All vaults require buttressing and a lateral thrust. A buttress is a projecting support built against a wall and counteracts with the lateral thrust. The octagonal room was innovative due it’s use of groin vaults, which were the earliest known examples in roman architecture. Also, this room featured vault haunch clerestory windows. In order to light the surrounding rooms of the main corridor, spaces were left between the vaults and the dome. This provided dramatic lighting, but it also expanded the interior space. The only main light source would have been from the dome’s oculus, but now the surrounding rooms received light as well. The dome itself was formed from a domical vault that flattened slightly at the top. Much of the dome’s weight rests on the eight piers that stood below. This dome, like other vaults in the Esquiline Wing, was cast from a wooden frame. Impressions can still be seen in the concrete from this framework.
