The longhouses inhabited by the Iroquois were wood boards/bark-covered structures of standardized design "in the shape of an arbor" about wide providing shelter for several related families. The longhouse had a -wide central aisle and -wide compartments, about long, down each side. The end compartments were usually used for storage. Hearths were spaced about apart down the aisle, with smoke holes in the roof. Two families shared each hearth. Each longhouse would house several generations of an extended family; a house was built proportionately to the number of families it was expected to contain and might be lengthened over time to accommodate growth. It is possible to infer the population of an Iroquois town from the sizes and number of longhouses it contained.