Firstly, family structures are changing. As Australia’s population continues to age, and grandparents live longer, it is becoming increasingly common for several generations to reside together, whether that is for cultural, lifestyle or financial reasons. With their smaller size and design versatility, granny flats give the occupants of a primary dwelling more living space and, in the case of detached buildings with a separate entryway, more privacy for the entire household. Grandparents have independence but proximity to the family, or if utilised as a ‘teenagers retreat’ or home office, middle-aged parents benefit from (much needed) peace and quiet.
Secondly, the deterioration in housing affordability in Australia has been a natural driver in the increased interest and demand for granny flats. For young adults finding it difficult to break into the residential property market, these secondary structures are often a good means to bridge the gap between moving out of the traditional family home and purchasing their first home. Granny flats enable parents to provide their children with a ‘starting space’ while they save for a deposit, or they can serve as a viable option for senior citizens who want to downsize and use their primary dwelling as a rental.
When it comes to planning requirements for granny flats across the nation, there are a number of similarities and differences. Typically granny flats are permitted in residential zones in each state or territory with varying requirements based on total site area, maximum floor area/floor space ratio, as well as open space and car parking requirements for both the existing dwelling and the proposed granny flat. For example, granny flats generally cannot be built on lots smaller than 450 square metres. In NSW the total floor area of a secondary dwelling cannot exceed 60 square metres, in comparison to 70 square metres in WA or 80 square metres in Queensland. Size restrictions of floor area often varies council to council within each state or territory.