The CNOS is sensitive to both household size and composition. As households pass through different life-cycle stages, their minimum housing requirements and actual utilisation of housing changes.

While having spare bedrooms indicates a capacity to accommodate more people in reasonable comfort, it does not necessarily mean that dwellings are not being fully utilised. Households may put these 'spare' rooms to various uses (e.g. study, office, gymnasium, craft or hobby room, children's play room, guest bedroom or store room). Some may provide each child with a separate bedroom regardless of their age or sex.

Australian Institute of Health and Welfare