New homes need roads, water, sewerage and power, and much of that work is done for the public sector. It might be expected to rise and fall with house building. Since 1988 it has not. Measured as annual growth, public engineering work on those four types of infrastructure has moved in the same direction as dwelling commencements in 73 of 152 quarters, about half the time, and the two have if anything moved against each other. Between the years to March 2012 and 2016 commencements rose 58.8% while this work fell 26.1%. Between the years to March 2022 and 2026 the work almost doubled, up 97.7%, while commencements fell 12.3%.
Node reading for Planning Regulations & Zoning Policy (21320): NIL RETURN. This article rests on the source data alone.
What is being compared
The comparison is between two ABS measures. One is the value of engineering construction work done for the public sector on roads, highways and subdivisions, water storage and supply, sewerage and drainage, and electricity: the public groundwork that new housing depends on. Its level, composition and recent growth are set out in Roads, Water and Power: The Public Groundwork Behind New Housing. The other is the number of new dwellings commenced each quarter, with dwellings approved as a check.
Both are summed over the four quarters to each quarter and compared with the same four quarters a year earlier. That removes their seasonal patterns and gives a rate of growth for each. The engineering figures are in current prices and cover all work of these types, including work that serves no new housing.
This is spending on infrastructure, not the contributions developers pay towards it. The two are different money. Contributions are collected by councils and state agencies and are not published in a national series; in New South Wales alone councils held $5.4 billion in contributions collected from developers at 30 June 2025, according to the NSW Audit Office.
Growth in the two series, quarter by quarter
Annual growth in public enabling work and in dwelling commencements, Australia
Per cent change in the four quarters to each quarter against the same four quarters a year earlier, June quarter 1988 to March quarter 2026. Enabling work is public-sector engineering work done on roads, water, sewerage and electricity, current prices. Source: ABS, Engineering Construction Activity, Australia, table 11; ABS, Building Activity, Australia, table 33.
The two lines do not track each other. Across the 152 quarters from June 1988 to March 2026 the correlation between the two growth rates is −0.23; against dwelling approvals it is −0.27. A correlation near zero means the growth of one says little about the growth of the other, and a negative sign means that, to the small extent they are related, they have tended to move in opposite directions. Since 2006 the correlation with commencements is −0.35. Allowing for a delay changes little. Where enabling work leads by up to 18 months the relationship stays negative; where commencements lead, it weakens and is close to zero at delays of 9 to 18 months. The strongest positive link found within three years is weak, 0.17, and comes when growth in enabling work is set against growth in commencements three years later (0.19 against approvals). That is consistent with some groundwork preceding house building by a few years, but it explains little of either series.
Two episodes
Change in public enabling work and in dwelling commencements over two four-year periods
Per cent change between years ending in the March quarter. Enabling work in current prices. Source: ABS, Engineering Construction Activity, Australia; ABS, Building Activity, Australia.
Two recent periods show the divergence. In the four years to March 2016, dwelling commencements rose from 147,480 to 234,258 a year, the most commenced in any year to March in the series, while public enabling work fell from $24.4 billion to $18.0 billion. In the four years to March 2026 the pattern reversed: enabling work rose from $23.6 billion to $46.7 billion, while commencements fell from 225,027 to 197,456.
The data does not say why. This work is commissioned by governments and their utilities for transport, water and electricity networks that serve more than new housing. The figures are consistent with a programme that runs on its own timetable rather than one that follows the housing cycle; they do not show which projects served new homes.
The scale of the groundwork against the homes being started
Public enabling work done per dwelling commenced, Australia
Thousands of dollars, current prices, years to March 1988 to 2026. The numerator is all public-sector engineering work on roads, water, sewerage and electricity, not only work serving new housing. Source: ABS, Engineering Construction Activity, Australia; ABS, Building Activity, Australia.
Set against the number of dwellings started, public enabling work rose from about $23,000 per dwelling commenced in the year to March 1989 to about $252,000 in the year to March 2025, and was about $236,000 in the year to March 2026. The ratio is not a cost per home. It is in current prices, so part of the rise reflects construction costs, and its numerator includes every public road, water, sewerage and electricity project, including those that serve existing communities and wider networks. It shows the scale of public groundwork relative to house building, which in each of the last three years has been higher than in any year before.
What this does not show
These are national totals of dollars spent, in current prices. They do not show how many lots were serviced, which projects served new housing, or whether infrastructure was a constraint on building in any particular place. A national series can hide regional patterns in which infrastructure and housing do move together, such as new estates on the urban fringe. The comparison shows co-timing only, and says nothing about cause in either direction. Contributions paid by developers are not measured here.
Findings are presented on the basis of data and evidence alone.
