I noticed in Isle of Man census returns that often there are more than one family per listed house. For example, in the 1861 census, just about every house in Nelson Street, Douglas appears to have more than one family in it.

Does this mean that there were separate flats, or that there were two or more families occupying the same living space? Would these houses have had a separate kitchen or a kitchen area, etc?

What kind of sewerage arrangements would these houses have?