To construct one (1) double storey dwelling to the rear of the existing dwelling (two (2) dwellings on a lot) and to subdivide the land into two (2) lots in a General Residential Zone (GRZ), buildings and works (and subdivision) in a Design and Development Overlay - Schedule 9 (DDO9), and within the Tree Protection Zone of substantial trees in a Significant Landscape Overlay - Schedule 4 (SLO4)