The Roman building is a reconstruction of a typical winter dining room from a Somerset villa. It measures 10m by 5.6m. The stone wall foundations are made of local blue lias on three sides and on the fourth side red sandstone reclaimed from a real Roman villa that was excavated in advance of the Cannington bypass.

The walls above the stone are of mass cob (clay subsoil, straw and small stones mixed with a little water) with 80 cm thickness reaching a height of 2.5m and require no wooden framework. They are covered with a lime render, that has been scratched and painted on three sides to give it the appearance of a stone wall made of large ashlar blocks. The gable ends above the cob are filled with wattle and daub.

Internally there is a raised Roman concrete floor on top of stone slabs supported on each corner by terra cotta tile columns called pillae, 0.6m high.

An underfloor hypocaust heating system is fed from an external furnace at the back of the building. The hot air fills the void under the floor and then exits via a series of tile-lined flues in the walls, which open to the outside just below the roof line. Adjustable metal plates act as wind baffles over the flue exits to prevent strong winds backing up the system.

The floor has a mosaic based on 4th century designs from nearby Hurcot and Bratton Seymour villas. Roughly 140,000 tesserae are needed for the mosaic floor – all made by hand using a hammer and hardie.

The plastered walls are painted in colours and styles known from the Roman period using the fresco technique. In the main room the dado (base strip) and top scroll are based on plaster from the villa near Brent Knoll. Columns and Christian symbols are based on ones from Lullingstone, ‘fried egg’ designs from Catterick (both 4th century) and generic fake marble panels. Figurative images are all deities, Flora godess of Spring (not margarine) and Bacchus god of wine and feasting are both based on early images fom Italy, while Diana, goddess of the hunt, is based on a 4th century image from Rome. The smaller room has designs based on Iwerne Minster (Dorset).

The roof is 5.6m high and consist of four oak trusses,  purlins and rafters, with boarding on top. Covering this are Roman style tegulae and imbrices roof tiles. Decorative antifix tiles line the bottom of the roof based on a double dolphin design from Caerleon (S. Wales) and a medusa head from Xanten (Germany).