Roman heating: how a hypocaust worked

Heating from below

A hypocaust warmed a room through the space beneath its floor. Supports, often stacks of tiles called pilae, carried the floor above a cavity connected to a furnace. Heat and combustion gases passed underneath; flues could then draw them through the walls and out of the building.

A system, not a fireplace in every room

Furnace position and the route of the flues affected which rooms received most heat. Bath suites used this arrangement for warm and hot spaces, and some prosperous homes heated selected rooms. It did not give every household modern central heating. Keeping it running required fuel, maintenance and work.

Recognise the remains

Exposed tile stacks were normally below the walking surface, not stools or room furnishings. Look for the furnace opening, the former floor level and any wall-flue tiles. At Canterbury the town house provides a clear case study; the Painted House at Dover offers another setting in which to connect decoration and comfort.