NSW Dual Occupancy Rules

A dual occupancy or duplex is where two dwellings are built on a single lot, either as an attached building with a common wall or as separate buildings. There are powerful financial reasons why this makes sense as it saves on land and construction costs.

Usually the land owner is building a dual occupancy with the intention to sell one or both dwellings to separate buyers. This requires subdivision of the original lot into two new lots either by Torrens (land only) or strata (land and air) subdivision.

Dual occupancies are permissible in many residential areas plus occasionally other zones. In addition to the land zone needing permissibility, the lot itself may also have to pass rules for minimum area and/or width for a dual occupancy to be permissible.
In New South Wales, the planning controls governing dual occupancies are unfortunately different in every Council.

Most projects in NSW are approved as a development application (DA) submitted to Council. However some projects can be approved much faster as a complying development certificate (CDC) submitted to a certifier instead. For CDC approval to be possible, a complex list of requirements must be satisfied by the lot and the proposed design.