What counts as floor area in an Australian property listing?

Start with the label, source and purpose

An area number is incomplete without its name and source. A marketing floor plan, planning application, registered strata plan and building statistics can all use different boundaries because they serve different purposes.

Ask what the figure is called in the source document, who prepared it and which spaces it includes. Do not silently translate “building area”, “total area” or “under roof” into internal living area.

Enclosed internal area

For buyer comparisons, enclosed internal dwelling area is often the clearest starting point. A practical convention is to follow the finished internal faces of the external walls and include enclosed rooms, hallways, built-in cupboards and other space inside that boundary.

That is a FloorSQ comparison convention, not a nationwide legal definition. For example, NSW BASIX uses a specific internal-floor-area definition for its own assessment purpose, while other documents may measure to wall centrelines or external faces.

• Keep the same wall boundary for every property.
• Calculate each level separately and state how stairs and voids are treated.
• Record built-in storage and enclosed utility rooms consistently.

Building area and gross floor area depend on context

In the cited ABS Building Activity data for new residential dwellings, floor area is measured to the outside of external walls and excludes unenclosed verandahs and carports outside that perimeter. The ABS also warns that some apartment data can include shared areas such as foyers, lifts and resident amenities.

NSW planning rules use their own gross-floor-area calculation and exclusions. That state-specific planning definition should not be presented as the universal meaning of GFA in every property advertisement.

List garages and outdoor areas separately

A garage, carport, balcony, terrace, deck, verandah or alfresco area may be valuable, but it is not the same as enclosed internal dwelling space. Whether it appears in a headline total depends on the document and measurement rule.

For a like-for-like comparison, show internal area first, then list garage or parking, covered outdoor area and open outdoor area separately. Combine them only when the comparison clearly labels the broader total.

• Internal estimate
• Garage or parking
• Covered outdoor area, including alfresco where relevant
• Balcony, terrace, verandah or open deck
• Other storage or detached structures

Strata area needs the registered documents

Strata area is not automatically the same as internal apartment area. A balcony, garage, car space, storage cage or courtyard may be part of the lot, common property or subject to exclusive-use arrangements, depending on the registered plan and by-laws.

For an apartment purchase, check the contract, strata plan and by-laws with a solicitor or conveyancer. A marketing floor plan can help you understand the layout, but it does not settle title boundaries.

Land area is not dwelling floor area

Land area describes the lot or block. It may be useful for a different price-per-square-metre calculation, but it cannot be substituted for the area of the dwelling. Label land-based and dwelling-based rates clearly so readers do not compare unlike figures.

A survey plan can show lot dimensions and boundaries without showing the building footprint or internal rooms. Use the correct source for the question you are trying to answer.