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Project Type


If the project involves only one dwelling:

  • Detached dwelling house

    • means a dwelling house which is not attached to any dwellings or buildings.
  • Attached dwelling house
    • means a dwelling house which is attached to another dwelling or building.
  • Dwelling above another building
    • means a dwelling which is above another building or dwelling.

You also need to enter the number of bedrooms in the dwelling, and indicate whether it is a secondary dwelling (see the definition below).

If the project includes multiple dwellings, the selections for project type are:

  • Single dwelling house

    • one dwelling house (either detached or attached) on its own lot of land.
  • Multi-dwelling house
    • one of multiple dwellings (either attached or detached) on one lot of land, each with access at ground level.
  • Residential flat building
    • a building containing 3 or more dwellings, but does not include multi-dwelling houses. 

For each dwelling/building type, you need to enter the number of buildings. For each residential flat building, you need to enter the number of dwellings. 

If you have a combination of dwelling/building types, find out how to enter details for a combination of dwelling/building types in the BASIX tool.

A BASIX certificate is not required where a development application is being made solely to subdivide land and does not involve the erection of a dwelling.

Other relevant definitions

  • Secondary dwelling (Granny flat or bedsitter)

    • means a self-contained dwelling that (a) is established in conjunction with another dwelling (the principal dwelling), (b) is on the same lot of land as the principal dwelling, and (c) is located within, or is attached to, or is separate from, the principal dwelling.
      Except for land in a rural zone, the total floor area of a secondary dwelling may not exceed 60m2.
  • Dual occupancy means 2 dwellings (either detached or attached) on one lot of land but does not include a secondary dwelling.
    A dual occupancy should be entered as 2 multi-dwelling houses.
Last updated: 27/09/2023