Do not compare advertised area figures until you know whether they include walls, balconies, garages, stairs or detached buildings.
Why headline areas are rarely equivalent
An apartment listing may quote internal area, strata area, total lot area or an internal-plus-balcony figure. A house listing may quote building area, living area, floor area under roof or a figure that includes a garage and alfresco space. The labels are not interchangeable.
The useful question is not simply “which property has more square metres?” It is “how much comparable, usable space does each property provide, and what other spaces are being bundled into the advertised total?”
What to separate for an apartment
Start with the enclosed area you can use privately. Then list balconies, winter gardens, storage cages and car spaces separately. Common corridors, lifts, lobbies and shared facilities may add value, but they are not the same as space inside the apartment.
Also check the source document. A marketing plan and a registered strata plan can use different boundaries and may round dimensions differently. FloorSQ can help assess the marketing plan, but it does not replace the registered strata plan.
- Enclosed internal space
- Exclusive balcony, courtyard or terrace
- Storage cage or basement room
- Car space and common property
What to separate for a house
For a freestanding house, separate enclosed living space from the garage, carport, verandah, deck, alfresco area and detached structures. In multi-level homes, confirm whether stairs and voids are counted once, twice or excluded under the stated convention.
A large “area under roof” figure can look attractive while including less enclosed living space than expected. Conversely, a well-planned smaller home can offer better furniture placement and flow than a larger home with a fragmented layout.
- Enclosed living area by level
- Attached or detached garage
- Covered outdoor area and open deck
- Studio, shed, basement and low-clearance space
Compare like with like
Create a small comparison table with the same categories for every property. Calculate price per square metre using comparable internal area first, then assess outdoor, parking and storage separately. This prevents a large garage or balcony from making one home look artificially cheap per square metre.
For example, calculate purchase price ÷ estimated internal area for each property, then add notes on layout, light, ceiling height, storage and flexibility. Price per square metre is a useful indicator, not a complete valuation model.
comparable price per m² = purchase price ÷ comparable internal areaWhat to ask before relying on the figure
Ask the agent what document the area came from, which boundary convention was used and whether external or ancillary areas are included. Request the registered plan or building documents where relevant and compare them with the marketing plan.
If the answer could affect your offer, obtain independent verification. FloorSQ is most useful for identifying figures that need a clearer explanation.