House in multiple occupation
A house in multiple occupation (HMO), or a rooming house, is a residential property occupied by more than one household which have shared 'common areas'. In the United Kingdom, this is called a 'house of multiple occupation', in North America it is a 'rooming house'.
Most such homes have been subdivided from larger houses, designed for and occupied by one family.
Some housing legislation makes a distinction between buildings occupied mainly on long leases and those where the majority of the occupants are short-term tenants. The legislation has its origins in fire safety legislation, following a series of publicised, preventable deaths in overcrowded buildings.