We’ve updated the eTool Residential Benchmark for Australia to reflect the most recent data and better represent the current mix of residential building types across the country. This update ensures that your project assessments align with the latest trends and statistics in Australian housing.
What’s New?
The benchmark now incorporates the latest dwelling approval data from the Australian Bureau of Statistics (ABS) for the 2024–25 financial year, released in July 2025. This data reflects a shift in the types of homes being built across Australia.
Dwelling Type Mix (FY 2024–25)
|
Dwelling Type |
% of Total Approvals |
|
Detached Houses |
60.6% |
|
Semi-Detached / Townhouses |
11.8% |
|
Low-Rise Apartments (1–3 storeys) |
11.8% |
|
High-Rise Apartments (4+ storeys) |
15.7% |
Source: New Dwelling Approvals – Australia (FY 2024–25, Original Terms)
Note: Minor dwelling types (e.g. boarding houses, group homes) account for ~2.2% and are excluded from the benchmark.
Floor Area
To estimate energy use and material impacts accurately, we’ve used the average floor areas reported by the ABS:
|
Dwelling Type |
Average Floor Area (m²) |
|
Detached Houses |
232.3 |
|
Semi-Detached / Townhouses |
151.0 |
|
Apartments (All Types) |
137.0 |
Source: Average Floor Area of New Residential Dwellings (April 2023).
The floor area of a building reported by ABS includes useable space in a building (and its attachments) at the final stage of its construction. The boundary of the recorded floor area of a building is delineated by the external perimeter of the exterior walls of the building including garage, common areas of apartments such as foyers, lifts and resident amenities are also included. The area under unenclosed verandas, carports, etc., attached outside the exterior walls of one or more storeys, is excluded.
For each of these density types, eTool have formulated a BCA code compliant building. We have then created a nominal statistical mix of floor areas to match the average new dwelling size (Fully Enclosed Covered Area) in Australia (196 m2). In this way we come up with a “dwelling” that is a mix of densities and matches the size of the average Australian dwelling.
The ABS does not provide a breakdown of conditioned floor area (spaces that are actively heated or cooled). To address this, we’ve used proportional estimates from CSIRO research on typical conditioned area ratios for Class 1 and Class 2 buildings for all Australian states for the period of one year 2024/2025 (Source: https://ahd.csiro.au/dashboards/design/area/).
In eTool, the Gross Floor Area (GFA) includes both fully enclosed spaces and unenclosed covered areas (UCA), such as verandahs, patios, balconies, and carports. However, there’s no fixed percentage for how much of a home’s area is considered UCA in Australia. This is because the size and presence of these spaces can vary a lot depending on the type of dwelling, the local climate, and common design practices.
For example, detached houses in warmer regions like Queensland or Northern Australia often have larger verandahs and patios to help with shading and cooling. In contrast, homes in cooler areas like Victoria or Tasmania usually have smaller outdoor covered spaces. Medium- and high-density homes, like townhouses and apartments, tend to have much smaller UCA, usually just balconies or small porches.
Because of these differences, there’s no one-size-fits-all percentage for UCA. Instead, we’ve based our assumptions on real-world examples, climate conditions, and professional experience to reflect typical Australian housing. In this benchmark, we’ve assumed that UCA is around 28% of the GFA. Based on this, the total GFA for our model residential dwelling is 274.8 m2. This figure represents an average across different dwelling types and regions in Australia.
Occupancy
The average number of persons per household in Australia remained stable at 2.6, according to the ABS Census 2021. Meanwhile, the average number of bedrooms per dwelling decreased slightly from 3.2 to 3.1, reflecting a gradual shift in housing design and occupancy patterns (Source: ABS Housing Occupancy and Costs – 2019–20)
Solar PV System
The assumptions relating to solar PV systems for Australian dwellings in this benchmark are based on typical conditions and national statistics. The focus is on detached and semi-detached houses, which together make up around 73% of all residential dwellings in Australia (Australian Bureau of Statistics, 2021 Census). These housing types are the most suitable for rooftop solar installations because they usually have sufficient roof space and independent ownership structures.
In this update, we’ve assumed a 6.6 kW solar PV system, which represents the most common size for Australian households according to the Clean Energy Regulator and Solar Choice data. This system size is generally compatible with standard single-phase power connections, making it accessible for most detached and semi-detached homes.
In line with national adoption trends, we’ve also assumed that around 40% of Australian homes have rooftop solar PV installed, based on figures reported by the Clean Energy Regulator (2024). This reflects Australia’s world-leading uptake of residential renewable energy.
