Household Formation Trends
Household Formation Trends (21430) measures how many new households form in a year: the change over four quarters in the number of private households. Households, not people, are what occupy dwellings, so this is the demographic demand that housing supply has to meet. Higher readings mean more households forming. It is a component of the APN Aggregate Demographic Index™ (21400), at a weight of 0.15.
Measure change, October 2026. Until October 2026 this node read formation in a single quarter, on a household-size input whose recent values could not be sourced. It now reads formation over four quarters, which removes the seasonal pattern of quarterly population growth, on the household count described here. The household count is modelled, not measured between Censuses: population multiplied by the share living in private dwellings and divided by average household size, both taken from ABS Household and Family Projections. Each edition’s base-year estimate (June 2011, 2016 and 2021) is used as an anchor and interpolated by quarter, and the 2021-based projection is followed from June 2021. Recent quarters therefore rest on the projection’s assumptions; the 2026 Census, published from 2027, will re-anchor them.
Primary metric: Node Z-Score (Z21430)
Metric typology: single-series Z-score of a four-quarter change in a modelled count.
| Input | Source | Frequency | Coverage |
|---|---|---|---|
| Estimated resident population, Australia | ABS National, state and territory population (3101.0), A2133251W | Quarterly | September quarter 1981 to March quarter 2026 |
| Average household size and non-private-dwelling share | ABS Household and Family Projections, Australia, Series II (2011-, 2016- and 2021-based editions) | Annual, interpolated by quarter | June 2011 to June 2026 |
Tier-1 sovereign statistical releases (ABS). No commercial data provider dependency exists within this node.
The chart shows the node’s reading in every quarter, measured against the 2011–2025 baseline.
The March quarter 2026 reading, −0.1217σ, ranks 36.2 against 59 quarters and sits inside the normal range of −1.2720σ to +0.8622σ. The highest ranked reading was +1.9984σ in the September quarter 2023, and the lowest −2.6156σ in the March quarter 2021.
Show the data
| Quarter | Reading | Basis |
|---|---|---|
| Q3 2011 | −0.8369σ | Ranked |
| Q4 2011 | −0.5445σ | Ranked |
| Q1 2012 | −0.2407σ | Ranked |
| Q2 2012 | +0.0545σ | Ranked |
| Q3 2012 | +0.1278σ | Ranked |
| Q4 2012 | +0.1746σ | Ranked |
| Q1 2013 | +0.1449σ | Ranked |
| Q2 2013 | +0.0799σ | Ranked |
| Q3 2013 | +0.0076σ | Ranked |
| Q4 2013 | −0.1401σ | Ranked |
| Q1 2014 | −0.1967σ | Ranked |
| Q2 2014 | −0.3366σ | Ranked |
| Q3 2014 | −0.3781σ | Ranked |
| Q4 2014 | −0.3767σ | Ranked |
| Q1 2015 | −0.4014σ | Ranked |
| Q2 2015 | −0.3899σ | Ranked |
| Q3 2015 | −0.3764σ | Ranked |
| Q4 2015 | −0.3463σ | Ranked |
| Q1 2016 | −0.2181σ | Ranked |
| Q2 2016 | −0.0570σ | Ranked |
| Q3 2016 | +0.2564σ | Ranked |
| Q4 2016 | +0.4697σ | Ranked |
| Q1 2017 | +0.6877σ | Ranked |
| Q2 2017 | +0.7785σ | Ranked |
| Q3 2017 | +0.7046σ | Ranked |
| Q4 2017 | +0.5407σ | Ranked |
| Q1 2018 | +0.5192σ | Ranked |
| Q2 2018 | +0.5313σ | Ranked |
| Q3 2018 | +0.6027σ | Ranked |
| Q4 2018 | +0.7030σ | Ranked |
| Q1 2019 | +0.6769σ | Ranked |
| Q2 2019 | +0.5779σ | Ranked |
| Q3 2019 | +0.5808σ | Ranked |
| Q4 2019 | +0.6248σ | Ranked |
| Q1 2020 | +0.5289σ | Ranked |
| Q2 2020 | +0.0815σ | Ranked |
| Q3 2020 | −1.0294σ | Ranked |
| Q4 2020 | −1.8217σ | Ranked |
| Q1 2021 | −2.6156σ | Ranked |
| Q2 2021 | −2.5075σ | Ranked |
| Q3 2021 | −2.5492σ | Ranked |
| Q4 2021 | −2.2488σ | Ranked |
| Q1 2022 | −1.5227σ | Ranked |
| Q2 2022 | −1.2093σ | Ranked |
| Q3 2022 | +0.0374σ | Ranked |
| Q4 2022 | +0.8194σ | Ranked |
| Q1 2023 | +1.3440σ | Ranked |
| Q2 2023 | +1.7288σ | Ranked |
| Q3 2023 | +1.9984σ | Ranked |
| Q4 2023 | +1.8363σ | Ranked |
| Q1 2024 | +1.5639σ | Ranked |
| Q2 2024 | +1.0332σ | Ranked |
| Q3 2024 | +0.4396σ | Ranked |
| Q4 2024 | +0.1566σ | Ranked |
| Q1 2025 | +0.0055σ | Ranked |
| Q2 2025 | −0.0326σ | Ranked |
| Q3 2025 | +0.0369σ | Ranked |
| Q4 2025 | −0.0778σ | Ranked |
| Q1 2026 | −0.1217σ | Ranked |
At −0.1217σ (Q1 2026), about 157,272 households formed in the year to March 2026, slightly below the 2011–2025 average of 162,289. Position. 36.2, ranked against 59 quarters since September 2011.
Formation fell to 54,406 in the year to March 2021, while the border was closed, and rose to 244,713 in the year to September 2023 as migration resumed, the most on record. It has eased since and has been close to its average through 2025.
The other components of the APN Aggregate Demographic Index™ (21400), and the series’ companion node.
- The population input is a Tier-1 sovereign statistical release (ABS), and household size comes from ABS projections
- The Z-score of −0.1217σ (Q1 2026) is derived directly from the inputs against the 2011–2025 baseline, not manually entered or estimated
- The position is an empirical percentile rank against 59 quarters
- The modelled household count, its re-anchoring at each Census and the change of measure are disclosed
