Roman architecture and construction methods were very sophisticated. Although Roman houses did not have the benefits of gas and electricity, and they had a lack of halls and corridors, we would have found them comfortable to live in.

Most Roman roof tiles were made out of a red clay called terracotta, which is familiar to us as plant pots. Tegulae tiles fitted together in rows to create the roof surface. A second type of tile, called an Imbrex was used to cover and overlap the joints. Terracotta was also used for decorative friezes around the tops of buildings.

Many Roman villas had an underfloor heating system called a hypocaust. The floor was supported by yet another sort of tile, called a pilae, arranged in stacks. Hot air circulated under the floor from a stove situated in a building outside the villa. The best rooms and bathhouses were given underfloor heating.

Columns of stone or wood, or intricately shaped bricks plastered and painted to look like stone were used to support the roof. The roof beams were generally made of wood, although shorter spans were created out of stone. Lead gutters and pipes channelled rainwater down from the roof into storage for the household.

Doors and window shutters were usually made of wood, sometimes reinforced with iron. For security ironwork grilles and gates were used and there were no windows facing out onto the street - all Roman houses faced inward. Instead of a solid wall of bricks or stone blocks, a Roman wall would have facings of brick or stone, a cavity in the centre filled with rubble, and a coating of plaster. Roman bricks were very large and flat by modern standards.

Common brick was mud brick, and even if it was cured for the recommended two years before use, it was still sensitive to moisture and weathering. This led to the practice of plastering walls inside and out, for more protection. In more ambitious buildings, the Romans used huge blocks of a volcanic, porous stone called Tufa. They clamped the blocks together with iron as a method of construction.

A roof protects a building and its inhabitants from heat, cold, rain, wind and snow. It needs to be both strong and light and also easy to mend. A tile is a thin slab of material, fixed and arranged in overlapping rows to form the roof.

This original Roman tile is made out of stone, and has been especially prepared by a stonemason skilled in carving stone into thin sections without splitting or cracking. Each tile was made to the same size, to allow uniformity when covering a large roof space. The underlying structure of a roof is a series of wooden beams creating a frame to which the tiles can be attached. Each tile has a hole at the top through which a nail can go, thus fixing the tile to the beam.

This tile is quite rough on the surface. You can still see the marks of the stone mason's tools where the excess stone was chipped away. The colours of the tile - greys and yellows - indicate that it is sandstone, a type of rock formed out of compressed sand. Two bright spots of yellow lichen remain on the tile, telling us which side faced the weather.