A 70m² granny flat can sound like a simple approval pathway for Perth homeowners. Under Western Australia’s updated ancillary dwelling rules, a compliant granny flat may avoid planning approval if it does not exceed 70m² and meets the relevant deemed-to-comply requirements. But there is one important detail many homeowners miss: 70m² is not the only rule. For homeowners in Canning Vale, Gosnells, Thornlie, Southern River, Armadale, Willetton, Melville, Cockburn, Canning, Belm