--- title: "21420 – Ageing Population & Housing Needs" url: https://australianproperty.network/apn-codex/series-20000/series-21000/series-21400/21420-ageing-population-housing-needs/ date: 2026-01-16 modified: 2026-10-06 lang: en author: "" description: "APN Codex Node 21420 21400 — Demographic Analysis Certified Ageing Population & Housing Needs Z-Score −0.1180σ Period Q1 2026 Position 75.9 of 175 qtrs Vintage 2026-Q4 1Node Definition Ageing Population..." word_count: 898 --- # 21420 – Ageing Population & Housing Needs - APN Codex Node 21420 21400 — Demographic Analysis Certified ### Ageing Population & Housing Needs Z-Score−0.1180σPeriodQ1 2026Position75.9 of 175 qtrsVintage2026-Q4 1Node Definition Ageing Population & Housing Needs (21420) measures how fast the population is ageing: the change over the year in the old-age dependency ratio, the number of people aged 65 and over for every 100 people aged 15 to 64. Higher readings mean the population ageing faster, which shifts demand towards the kinds of housing older households need. It is a component of the APN Aggregate Demographic Index™ (21400), at a weight of 0.30. Known limitations **Measure change, October 2026.** Until October 2026 this node read the level of the dependency ratio, which rises almost in a straight line (a correlation with time of 0.99 over 2011–2025), so its position measured the date rather than conditions. The node now reads the rate of ageing, and the level is shown as context. Because the ratio divides older residents by working-age residents, migration, which is mostly of working age, slows the reading when it rises and speeds it up when it falls. 2Metric Definition **Primary metric: Node Z-Score (Z21420)** Z-Score Construction Current (Q1 2026)−0.1180σ RtOld-age dependency ratio, end of quarter t: 27.24 people aged 65+ per 100 aged 15–64 at March 2026, 26.81 a year earlier ΔRtChange over four quarters: +0.43 per 100 in the year to March 2026 μ, σBaseline mean and sample standard deviation of the change, 2011–2025 (+0.45 and 0.20, 60 quarters) **Metric typology:** single-series Z-score of a four-quarter change in a ratio. 3Data Sources | Input | Source | Frequency | Coverage | | ----- | ------ | --------- | -------- | | Estimated resident population by single year of age, Australia | ABS National, state and territory population (3101.0), through the ABS Data API (ERP_Q) | Quarterly | September quarter 1981 to March quarter 2026 | Tier-1 sovereign statistical releases (ABS). No commercial data provider dependency exists within this node. 4Reading History The chart shows the node’s reading in every quarter, measured against the 2011–2025 baseline. Ageing Population & Housing Needs (21420) · Reading HistoryNode Z-Score by Quarter, March 2011 to March 2026−0.1180σ · position 75.9, ranked against 175 quarters**Reading, ranked quarters**Normal range (middle 80% of ranked quarters)**Current readingThe March quarter 2026 reading, −0.1180σ, ranks 75.9 against 175 quarters and sits inside the normal range of −1.7272σ to +0.1805σ. The highest ranked reading was +2.3096σ in the March quarter 2021, and the lowest −2.3932σ in the June quarter 2023. Show the data | Quarter | Reading | Basis | | ------- | ------- | ----- | | Q3 1982 | −1.6853σ | Ranked | | Q4 1982 | −1.7267σ | Ranked | | Q1 1983 | −1.7292σ | Ranked | | Q2 1983 | −1.6732σ | Ranked | | Q3 1983 | −1.5429σ | Ranked | | Q4 1983 | −1.5211σ | Ranked | | Q1 1984 | −1.5395σ | Ranked | | Q2 1984 | −1.6190σ | Ranked | | Q3 1984 | −1.4971σ | Ranked | | Q4 1984 | −1.4215σ | Ranked | | Q1 1985 | −1.3437σ | Ranked | | Q2 1985 | −1.2637σ | Ranked | | Q3 1985 | −1.2520σ | Ranked | | Q4 1985 | −1.1110σ | Ranked | | Q1 1986 | −0.9707σ | Ranked | | Q2 1986 | −0.8165σ | Ranked | | Q3 1986 | −0.7627σ | Ranked | | Q4 1986 | −0.8987σ | Ranked | | Q1 1987 | −1.0010σ | Ranked | | Q2 1987 | −1.0896σ | Ranked | | Q3 1987 | −1.1559σ | Ranked | | Q4 1987 | −1.2130σ | Ranked | | Q1 1988 | −1.3555σ | Ranked | | Q2 1988 | −1.3912σ | Ranked | | Q3 1988 | −1.4559σ | Ranked | | Q4 1988 | −1.3908σ | Ranked | | Q1 1989 | −1.3013σ | Ranked | | Q2 1989 | −1.2653σ | Ranked | | Q3 1989 | −1.3457σ | Ranked | | Q4 1989 | −1.4234σ | Ranked | | Q1 1990 | −1.4520σ | Ranked | | Q2 1990 | −1.4603σ | Ranked | | Q3 1990 | −1.1629σ | Ranked | | Q4 1990 | −0.9378σ | Ranked | | Q1 1991 | −0.8185σ | Ranked | | Q2 1991 | −0.7235σ | Ranked | | Q3 1991 | −0.8012σ | Ranked | | Q4 1991 | −0.8244σ | Ranked | | Q1 1992 | −0.8265σ | Ranked | | Q2 1992 | −0.9122σ | Ranked | | Q3 1992 | −0.9072σ | Ranked | | Q4 1992 | −0.8962σ | Ranked | | Q1 1993 | −0.8511σ | Ranked | | Q2 1993 | −0.7403σ | Ranked | | Q3 1993 | −0.7700σ | Ranked | | Q4 1993 | −0.8347σ | Ranked | | Q1 1994 | −0.9204σ | Ranked | | Q2 1994 | −1.0408σ | Ranked | | Q3 1994 | −1.2391σ | Ranked | | Q4 1994 | −1.2796σ | Ranked | | Q1 1995 | −1.3158σ | Ranked | | Q2 1995 | −1.4204σ | Ranked | | Q3 1995 | −1.3229σ | Ranked | | Q4 1995 | −1.4201σ | Ranked | | Q1 1996 | −1.4103σ | Ranked | | Q2 1996 | −1.3662σ | Ranked | | Q3 1996 | −1.4907σ | Ranked | | Q4 1996 | −1.4620σ | Ranked | | Q1 1997 | −1.5081σ | Ranked | | Q2 1997 | −1.4678σ | Ranked | | Q3 1997 | −1.4741σ | Ranked | | Q4 1997 | −1.4840σ | Ranked | | Q1 1998 | −1.5373σ | Ranked | | Q2 1998 | −1.5829σ | Ranked | | Q3 1998 | −1.5476σ | Ranked | | Q4 1998 | −1.5757σ | Ranked | | Q1 1999 | −1.5902σ | Ranked | | Q2 1999 | −1.6287σ | Ranked | | Q3 1999 | −1.6392σ | Ranked | | Q4 1999 | −1.7071σ | Ranked | | Q1 2000 | −1.7366σ | Ranked | | Q2 2000 | −1.7546σ | Ranked | | Q3 2000 | −1.6638σ | Ranked | | Q4 2000 | −1.5335σ | Ranked | | Q1 2001 | −1.5068σ | Ranked | | Q2 2001 | −1.3941σ | Ranked | | Q3 2001 | −1.4449σ | Ranked | | Q4 2001 | −1.6033σ | Ranked | | Q1 2002 | −1.5295σ | Ranked | | Q2 2002 | −1.6973σ | Ranked | | Q3 2002 | −1.7978σ | Ranked | | Q4 2002 | −1.7699σ | Ranked | | Q1 2003 | −1.8220σ | Ranked | | Q2 2003 | −1.7850σ | Ranked | | Q3 2003 | −1.7152σ | Ranked | | Q4 2003 | −1.6533σ | Ranked | | Q1 2004 | −1.6652σ | Ranked | | Q2 2004 | −1.6218σ | Ranked | | Q3 2004 | −1.5751σ | Ranked | | Q4 2004 | −1.5747σ | Ranked | | Q1 2005 | −1.5848σ | Ranked | | Q2 2005 | −1.5908σ | Ranked | | Q3 2005 | −1.6099σ | Ranked | | Q4 2005 | −1.6547σ | Ranked | | Q1 2006 | −1.7276σ | Ranked | | Q2 2006 | −1.7861σ | Ranked | | Q3 2006 | −1.6708σ | Ranked | | Q4 2006 | −1.5927σ | Ranked | | Q1 2007 | −1.5365σ | Ranked | | Q2 2007 | −1.4676σ | Ranked | | Q3 2007 | −1.5965σ | Ranked | | Q4 2007 | −1.6914σ | Ranked | | Q1 2008 | −1.7999σ | Ranked | | Q2 2008 | −1.9042σ | Ranked | | Q3 2008 | −1.8601σ | Ranked | | Q4 2008 | −1.7464σ | Ranked | | Q1 2009 | −1.6013σ | Ranked | | Q2 2009 | −1.3509σ | Ranked | | Q3 2009 | −1.0782σ | Ranked | | Q4 2009 | −0.8424σ | Ranked | | Q1 2010 | −0.5611σ | Ranked | | Q2 2010 | −0.3806σ | Ranked | | Q3 2010 | −0.1722σ | Ranked | | Q4 2010 | −0.0845σ | Ranked | | Q1 2011 | −0.0520σ | Ranked | | Q2 2011 | −0.0486σ | Ranked | | Q3 2011 | +0.0827σ | Ranked | | Q4 2011 | +0.2171σ | Ranked | | Q1 2012 | +0.3583σ | Ranked | | Q2 2012 | +0.5397σ | Ranked | | Q3 2012 | +0.2920σ | Ranked | | Q4 2012 | +0.2362σ | Ranked | | Q1 2013 | +0.1613σ | Ranked | | Q2 2013 | +0.1134σ | Ranked | | Q3 2013 | +0.1988σ | Ranked | | Q4 2013 | +0.1933σ | Ranked | | Q1 2014 | +0.1519σ | Ranked | | Q2 2014 | +0.1125σ | Ranked | | Q3 2014 | +0.0781σ | Ranked | | Q4 2014 | +0.1156σ | Ranked | | Q1 2015 | +0.1090σ | Ranked | | Q2 2015 | +0.1125σ | Ranked | | Q3 2015 | +0.1223σ | Ranked | | Q4 2015 | +0.1250σ | Ranked | | Q1 2016 | +0.1146σ | Ranked | | Q2 2016 | +0.1317σ | Ranked | | Q3 2016 | +0.0367σ | Ranked | | Q4 2016 | −0.0682σ | Ranked | | Q1 2017 | −0.2063σ | Ranked | | Q2 2017 | −0.2625σ | Ranked | | Q3 2017 | −0.3279σ | Ranked | | Q4 2017 | −0.1943σ | Ranked | | Q1 2018 | −0.0970σ | Ranked | | Q2 2018 | −0.0415σ | Ranked | | Q3 2018 | +0.0492σ | Ranked | | Q4 2018 | +0.0165σ | Ranked | | Q1 2019 | −0.0247σ | Ranked | | Q2 2019 | +0.0571σ | Ranked | | Q3 2019 | +0.2580σ | Ranked | | Q4 2019 | +0.6846σ | Ranked | | Q1 2020 | +1.0708σ | Ranked | | Q2 2020 | +1.3864σ | Ranked | | Q3 2020 | +2.0209σ | Ranked | | Q4 2020 | +2.0823σ | Ranked | | Q1 2021 | +2.3096σ | Ranked | | Q2 2021 | +2.1501σ | Ranked | | Q3 2021 | +1.8054σ | Ranked | | Q4 2021 | +1.2682σ | Ranked | | Q1 2022 | +0.3549σ | Ranked | | Q2 2022 | −0.2587σ | Ranked | | Q3 2022 | −1.2656σ | Ranked | | Q4 2022 | −1.8241σ | Ranked | | Q1 2023 | −2.1574σ | Ranked | | Q2 2023 | −2.3932σ | Ranked | | Q3 2023 | −2.3366σ | Ranked | | Q4 2023 | −2.0578σ | Ranked | | Q1 2024 | −1.7168σ | Ranked | | Q2 2024 | −1.2265σ | Ranked | | Q3 2024 | −0.8089σ | Ranked | | Q4 2024 | −0.5677σ | Ranked | | Q1 2025 | −0.3961σ | Ranked | | Q2 2025 | −0.2941σ | Ranked | | Q3 2025 | −0.2953σ | Ranked | | Q4 2025 | −0.1948σ | Ranked | | Q1 2026 | −0.1180σ | Ranked | Z-Score−0.1180σQ1 2026Position75.9ranked against 175 quartersChange over the year+0.43 per 100to March 2026Dependency ratio27.24per 100 aged 15–64, contextFastest ageing+0.92March 2021Slowest ageing−0.03June 2023 5Analytical Interpretation At −0.1180σ (Q1 2026), the population aged at about its usual pace: the dependency ratio rose 0.43 per 100 in the year to March 2026, to 27.24, against a 2011–2025 average rise of 0.45. **Position.** 75.9, ranked against 175 quarters since September 1982: ageing in the 2010s and 2020s is faster than in the 1980s and 1990s, so an average recent reading ranks high in the longer record. Ageing was fastest in the year to March 2021 (+0.92), while the border was closed and few working-age migrants arrived, and briefly reversed in the year to June 2023 (−0.03), when migration surged. It has returned towards its usual pace since. 6Other Components The other components of the APN Aggregate Demographic Index™ (21400), and the series’ companion node. [21410 →Population Growth & DistributionPopulation growth over the year. Q1 2026: −0.1883σ, 49.4 of 175 quarters. Weight 0.25.](https://australianproperty.network/apn-codex/series-20000/series-21000/series-21400/21410-population-growth-distribution/)[21430 →Household Formation TrendsHouseholds formed over the year. Q1 2026: −0.1217σ, 36.2 of 59. Weight 0.15.](https://australianproperty.network/apn-codex/series-20000/series-21000/series-21400/21430-household-formation-trends/)[21440 →Demographic Trend AnalysisThe change over the year in people aged 65+ per 100 households. Q1 2026: +0.3915σ, 75.9 of 59. Weight 0.30.](https://australianproperty.network/apn-codex/series-20000/series-21000/series-21400/21440-demographic-trend-analysis/)[21450 →Household Economic Cohort AnalysisPensioner and beneficiary living-cost growth less CPI growth, outside the composite. Q2 2026: +1.2242σ, 80.6 of 73.](https://australianproperty.network/apn-codex/series-20000/series-21000/series-21400/21450-household-economic-cohort-analysis/)[Parent index →21400 — Demographic Analysis (APN Aggregate Demographic Index™)](https://australianproperty.network/apn-codex/series-20000/series-21000/series-21400/) 7Certification Statement APN Codex Node 21420 — Ageing Population & Housing Needs — Certified The input is a Tier-1 sovereign statistical release (ABS)- The Z-score of −0.1180σ (Q1 2026) is derived directly from the input against the 2011–2025 baseline, not manually entered or estimated- The position is an empirical percentile rank against 175 quarters- The change from the level to the rate of ageing, and the effect of migration on the ratio, are disclosed **Certified:** 5 October 2026 **Source tier:** Tier-1 sovereign statistical agency (ABS) ##### Node Parameters Node21420 Series21400 StatusCertified Z-Score−0.1180σ Position75.9 of 175 qtrs PeriodQ1 2026 Vintage2026-Q4 Baseline μ+0.45 Baseline σ0.20 Baseline N60