The coal hole allowed the easy delivery of coal, generally in sacks and often from horse drawn carts, to the house's coal bunker. The location of the coal hole on the street minimised the distance the sacks needed to be carried and meant that dusty sacks and delivery men did not need to enter the house.
The hatch is typically about 12 to 14 inches (30 to 35 cm) in diameter and consists of a cast iron ring set into the pavement, with a circular cover, often made of cast iron alone but sometimes containing concrete or glass panes or small ventilation holes. Hatches have an internal latch that prevents the cover being lifted from the outside. On some streets there are a variety of types of cover reflecting the fact that the coal holes were installed at different times by different builders after the houses were built.