The buildings of Iron Age Italy (ca. 900 BCE) influenced the structures of the early period, made either of wood or of mud and brick, the latter being more durable and less prone to fire. By the second and first centuries, limestone and other stone materials were used. White marble and granite were prized for decorative purposes.

Perhaps the most important development the Romans made in construction was the invention of concrete (first known use in Palestria, Italy in 200 BCE). Vitruvius (ca. 100 BCE) in his book on architecture describes it as crushed stone, lime and sand, with pozzolana (the volcanic sand from the Baia region in Italy) being the best choice for the last ingredient. Concrete was important in the making of Rome’s famed vaults and arches, which would require exceptional skill in shaping stones otherwise to make them fit perfectly. And of course, concrete is perhaps the most influential of all inventions in the history of construction. A world without concrete would be very different from what it today. It is used in virtually every construction project, from skyscrapers to bridges to dams.

Along with concrete, the stones were locked together with iron pegs which fit into sockets in adjacent blocks and were held in place with molten lead, acting as dowels. The lead was poured into the sockets through a previously made channel after the stones were positioned.

Wood was also common in construction, some walls being made of a wooden frame filled with concrete and stones. It was also used as flooring, roofing and in frames for doors and windows. Bronze was another material used extensively; it found place in hinges, handles and keys, as well as in gilded tiles and sheaths for beams. Bronze sheets were used to decorate doors and adorn ceilings.

To transport water throughout its empire, the Romans built aqueducts, man-made channels of water connecting streams to water tanks in the urban areas. The most challenging aspect of building one was to keep it perfectly level so that water would continue to flow in the right direction. To do this, they used a column of water as a spirit level of sorts. Water channels were supported above ground level by stone and cement columns. The arch was an important structural feature as it helped distribute the weight of the channel onto the columns. An important example of Roman aqueducts, the Aqua Appia, was built around 320 BCE.

To protect their territories against attack, the Romans used a form of fortification in which a trench encircled the area and guard posts were erected at fixed intervals. Ahead of the trenches, rows of spikes were set into the ground and sometimes booby traps were also made. Roman walls of the later empire were thick structures with concrete used to bind stones together. The walls were faced with stone or brick. To fortify passages near bodies of water, cement that could set under water was used.

Since Romans largely used stone for their construction, they required chisels, hammers and files to shape the blocks. Emery powder was then rubbed over the surface to form a smooth finish.

The Romans used cranes to lift heavy blocks into position. These consisted of a rope-and-pulley system, with the ropes wound about a winch so that they could be raised by winding it. The crane system was a very important development, evolving over the centuries to the modern giants which lift everything from construction material to ship cargo. The use of it by the Romans is a further gauge of their technical expertise.