Plain-English guides to the bigger building decisions: two homes on one block, rebuilding or renovating, and building on a slope. NSW rules, from Sutherland Shire to Wollongong.
"Dual occupancy" is the NSW planning term for two dwellings on one lot; a duplex is the attached version. What changes your options is title: subdivided, each half becomes a semi-detached dwelling that can be sold on its own.
Read the guideRenovate when the structure is sound and the layout mostly works. Knock down and rebuild when you would be replacing the footings, roof, services and floor plan anyway: a new home priced from a complete design is often the more certain path.
Read the guideA detached dual occupancy gives two households a full-size home each on one lot, with its own entry, kitchen and yard. It suits parents and adult children who want to live close, and keeps the option of subdividing and selling one home later.
Read the guideStart from the land: a detail survey and a geotechnical report come before the floor plan, because the fall, soil and drainage decide the footings, retaining and number of levels. Split-level designs that follow the contour usually dig less and retain less.
Read the guideFor approvals and costs in Sutherland Shire, see the approvals guide and the building cost guide.