How big is a granny flat in NSW
Minimum Site Requirements for a granny flat:
Property must have a minimum 12 metre width at the building line of the existing dwelling. If your property does not meet this requirement you are able to apply for an attached granny flat. Maintain a 3m setback from the rear, 0.9m setback from the side boundaries.
Maximum floor area permissible for a Granny Flat is 60 m² Must have a 24m² courtyard space for the Granny Flat, with an area of at least 4m wide.