Fifteen Years of Inflation in the Housing Cost Base: A Structural Assessment
The record of Inflation (21220) runs from March 2011 to June 2026. It contains the low-inflation decade before the pandemic, the price increases of 2021 to 2023, a period of easing through 2024 and early 2025, and a renewed rise from the second half of 2025. The node combines five equally weighted inputs: headline CPI, the CPI housing group, trimmed mean CPI, the producer price index for house construction, and consumer inflation expectations. Its certified composite for the June quarter 2026 is +2.1049σ, ranked 100.0 against 22 quarters, the first reading above two standard deviations in that population. Viewed across fifteen years, the question the node answers is not whether inflation is high this quarter, but how far the cost base of Australian housing has been repriced, how quickly, and through which channels.
The central structural finding: a repricing concentrated in five years
Between the March quarter 2011 and the June quarter 2026, the CPI housing group rose 68.7 per cent, headline CPI 49.8 per cent, trimmed mean CPI 49.1 per cent and house construction producer prices 83.3 per cent. The cost of housing, and above all the cost of building it, rose materially faster than prices generally.
That repricing was not spread evenly. In the nine and three-quarter years to the December quarter 2020, the housing group rose 24.4 per cent and construction producer prices 24.7 per cent. In the five and a half years since, the housing group rose 35.6 per cent and construction producer prices 47.0 per cent, against 25.7 per cent for headline CPI. More than half of the fifteen-year increase in housing costs, and more than two-thirds of the increase in construction costs, occurred in the most recent five and a half years.
December 2020 → June 2026: Housing +35.6% · Headline +25.7% · Trimmed Mean +23.9% · Construction +47.0%
Index level change, per cent. Construction is the ABS producer price index for house construction.
A persistent level, an episodic pace
Measured on its five inputs, the composite has read above +1σ in every quarter from the December quarter 2022 to the June quarter 2026, fifteen consecutive quarters, and moved above +2σ for the first time in the June quarter 2026. The housing group input shows the same pattern: above +1σ since the December quarter 2022, and above +2σ since the September quarter 2025, reaching +2.5220σ in the June quarter 2026, the highest reading in its record.
This persistence is partly structural in construction. Four of the five inputs are price levels standardised against their 2011–2025 average; a price level that keeps rising at any positive rate moves further from that average. A year of inflation at 2.5 per cent adds roughly +0.28σ to headline CPI at its current level. The composite’s elevated reading is therefore best read as accumulated repricing that has not reversed. On the four price-level inputs it cannot reverse without prices falling or the baseline being re-anchored.
The pace of housing cost growth is not persistent in the same way. Measured as annual growth, housing costs ran ahead of headline CPI from the December quarter 2021 to the June quarter 2024, peaking at 3.28 percentage points in the September quarter 2022; ran behind it from the September quarter 2024 to the June quarter 2025; and have run ahead again since the September quarter 2025, by 2.86 percentage points in the June quarter 2026 (6.80 per cent against 3.94 per cent). The level has risen across the period, apart from a small dip in the second half of 2024; the housing-specific pace has come and gone in episodes.
The construction-cost channel and its governance significance
In the 2021–22 episode, construction producer prices led: their annual growth reached 8.85 per cent in the September quarter 2021, while the housing group was rising 1.53 per cent, and housing cost growth followed to 10.61 per cent by the December quarter 2022. In the current episode the order reversed. Housing cost growth re-accelerated to 4.77 per cent in the September quarter 2025 while construction producer prices were rising 0.52 per cent; construction cost growth followed, reaching 5.92 per cent in the June quarter 2026, and the construction index moved above +2σ for the first time in the March quarter 2026.
The governance significance is that no single channel can be relied on as the early signal. A response calibrated to construction input costs alone would have identified the 2021 episode early and the 2025 episode late. The policy response has since been material: the Reserve Bank raised the cash rate from 3.60 per cent to 4.35 per cent across February, March and May 2026, and from 1 February 2026 APRA limited new residential mortgage lending at a debt-to-income ratio of six or more to 20 per cent of each bank’s new lending. Those measures act on demand and credit. The construction-cost component of the repricing sits on the supply side, where cash rate settings act slowly and indirectly.
A second governance question follows from the level construction. A composite whose price-level inputs cannot fall while prices rise will tend to keep reporting a Two Standard Deviation Event through any period of positive inflation, unless expectations fall far enough to offset them. Whether the 2011–2025 baseline still describes the equilibrium against which housing costs should be judged, or whether the repricing since 2020 is permanent and warrants a new anchor, is a governance decision rather than a data question. The certified record establishes the size of the repricing; it does not decide which baseline should measure it.
The forward architecture — what would change the structural assessment
1. Pace convergence. Annual housing cost growth returning to or below headline CPI growth, as it did from the September quarter 2024 to the June quarter 2025, would end the current housing-specific episode even while the composite level remains elevated. This is the clearest available signal that housing is no longer repricing faster than the general basket.
2. Construction-cost deceleration. Annual growth in house construction producer prices returning from 5.92 per cent toward the low single-digit rates recorded through 2025 would indicate the supply-side component easing. Given the channel’s changed timing, this would confirm rather than anticipate a slowdown in housing costs.
3. Expectations re-anchoring. Consumer inflation expectations returning from 5.47 per cent toward their baseline average of 4.73 per cent would be the first input able to lower the composite during a period of positive inflation, since the four price-level inputs cannot. It would indicate that households no longer expect the current pace to continue.
A repricing of the housing cost base concentrated in the years since 2020, measured on a composite whose price-level inputs cannot fall while prices rise, with a housing-specific pace that has reopened since the September quarter 2025.
Findings are presented on the basis of data and evidence alone.
