Example showing how the BOT ontology can be used to describe the topology of a building. The building has four external walls and consists of 2 storeys. In the first storey there are rooms 101 and 102. In the second storey there is room 201. Room 101 has an entrance door, one window and a table. Room 102 has a window and a sofa. A door connects room 101 and room 102. A trapdoor connects room 102 and room 201.