Wealthy London residents are extending many floors beneath their homes . The aim is to increase their value and provide extra room . Comment: `` Our members have become increasingly worried by the nastiness of having great big holes dug next door to them , '' said Terence Bendixson , honorary secretary of planning at the Chelsea Society . Some have installed swimming pools , gyms and cinemas in their extended basements .
Wealthy London residents are extending many floors beneath their homes . The aim is to increase their value and provide extra room . Comment: Some have installed swimming pools , gyms and cinemas in their extended basements .