Hedonic Dwelling Value Indices
Node Definition
Hedonic Dwelling Value Indices (21111) tracks the quality-adjusted movement in Australian national dwelling values — the change in what an equivalent basket of housing is worth over time, rather than a simple median or mean transaction price, which shifts with compositional change in what happens to sell in a given period.
This reading is built from 34 quarterly observations — a shorter history than most APN Codex composites, because national hedonic dwelling-value reporting from this data provider only began in August 2017. The certified Z-score is unaffected in its construction, but a smaller baseline sample carries more uncertainty than a longer one.
The underlying figures are twelve-month rolling changes, so consecutive quarters share most of the same underlying months and are not independent of one another. The effective sample size is smaller again than the quarter count alone suggests.
Metric Definition
Primary metric: National Dwelling Value 12-Month Change, Z-Score
Metric typology: single-vector Z-score index, sole driver of the node reading. The Z-score is built from the 12-month percentage change in dwelling values, not the index level itself — index levels trend upward over long periods by construction and are not meaningfully standardised against a fixed baseline.
Data Sources
Cotality Home Value Index, National (All Dwellings) — a hedonic, quality-adjusted index published monthly. The certified series covers August 2017 to December 2025 as its baseline, with current readings continuing beyond that window. Cotality did not publish a distinct national figure before August 2017; earlier data covered combined capital cities only, so this is the true start of the series rather than a gap in sourcing.
A second provider’s national index (PropTrack Home Price Index) is tracked in reserve as a candidate future input, pending a weighting decision — it is not yet blended into this node’s certified reading.
Analytical Interpretation
At −0.5842σ, national dwelling values are running below their certified baseline mean: the twelve-month change has eased to 0.0% in the year to September 2026, against a baseline mean of 4.38%. The trajectory across the most recent four quarters has turned down — from +0.0561σ in Q3 2025, through a rise to +0.7365σ by Q1 2026, to the current −0.5842σ, the lowest reading since the June quarter 2023. The wider baseline history is considerably more volatile: certified quarterly readings have ranged from double-digit negative growth in 2022–23 to over +20% annual growth at the peak of the 2021 boom, so the current reading sits inside a genuinely wide historical range rather than at either end.
Position. 25.7, ranked against 36 quarters of the node’s record.
An independent second provider, PropTrack, reported a national increase of 0.1% over the twelve months to September 2026 in its own index, down from 5.8% over the twelve months to June — consistent with the flat twelve-month change behind this reading, though PropTrack is not currently blended into this node’s certified Z-score.
Other Components
The other component of National Market Reports (21110).
Certification Statement
Hedonic Dwelling Value Indices (21111) holds Active status. The certified Z-score is −0.5842σ (Q3 2026, N=34). Both limitations described in Section 1 — the shorter available baseline history and the overlapping-window construction of the underlying twelve-month change figures — are permanent, disclosed features of this reading, not defects expected to be resolved by a future data refresh.
