On a quiet street in Ainslie, one of Canberra's oldest garden suburbs, a resident watches surveyors peg out the block next door — a low brick cottage under a stand of mature eucalypts that has stood since the 1920s, and that under the ACT's new Territory Plan can now be redeveloped into three narrow townhouses instead of one house. A short drive away in Gungahlin, a young public servant family is signing a lease at a rent higher than any recorded in Canberra's history, in a city where a rental home now sits vacant for well under one week in a hundred before someone takes it (Domain Rental Report, Mar-2026 quarter, approx.). Both scenes sit inside the same policy problem. The ACT government has decided that most of Canberra's future growth must happen inside its existing suburbs rather than on its fringes, and in the past three years it has rewritten the planning system to make that possible. The resident in Ainslie and the family in Gungahlin are, in different ways, both waiting to see whether that rewrite actually works.
What the government did
The ACT's planning system has been in a state of live reconstruction since the Planning Act 2023 passed the Legislative Assembly on 6 June 2023 and the bulk of the new system commenced on 27 November 2023, replacing the Planning and Development Act 2007 and the Territory Plan 2008 with a new Territory Plan built around "outcomes-based" rules rather than detailed mandatory codes (Planning Act 2023 (ACT); City and Environment Directorate, "The new Planning Act", 2023-24). The stated goal was a faster, more predictable system that judged proposals on the quality of what they delivered rather than a checklist of measurements.
The most contested piece of that rebuild is the "missing middle" reform — townhouses, terraces and low-rise apartments in suburbs that have, since Canberra was built, allowed only single detached houses on most blocks. Zoned RZ1 (Suburban) and RZ2 (Suburban Core), these blocks cover most of established Canberra. Draft Plan Amendment 04 (DPA-04), released for comment and referred to a Legislative Assembly committee on 28 October 2025, proposed allowing multi-unit housing — duplexes, triplexes, terraces and apartments up to two storeys plus an attic in RZ1, and up to three storeys plus an attic in RZ2 — on blocks that had never permitted it. After the Assembly's Standing Committee on Environment and Planning took 26 submissions, held public hearings on 10 and 12 February 2026 and tabled its Report 6 on 30 April 2026 recommending approval with tighter settings on parking, streetscape character and tree canopy, Planning Minister Chris Steel approved the reform as Major Plan Amendment 04 on 22 May 2026 (ACT Legislative Assembly, Standing Committee on Environment and Planning, Report 6, 30-Apr-2026; CMTEDD media release, "More choice, more homes", 22-May-2026). The government has framed the change as central to its target of enabling around 30,000 additional homes by 2030 (approx.) (CMTEDD media release, 22-May-2026), sitting inside a broader "70/30" strategy — up to 70 per cent of new housing built within Canberra's existing urban footprint and 30 per cent on greenfield land — first set out in the ACT Planning Strategy 2018.
The strongest case
A capital that cannot keep eating bushland
The government's argument deserves to be stated in full before it is tested, because on its own terms it is coherent. Canberra needs a great many more homes: the Territory's own planning strategy has put the figure at up to 100,000 additional dwellings by 2041 to keep pace with population growth, and the ABS recorded the ACT's population growing by 6,200 people, or 1.3 per cent, in 2024-25 alone (ACT Planning Strategy 2018; ABS, Regional population, 2024-25 financial year). Every one of those blocks that goes to a new greenfield suburb on Canberra's edge comes with new roads, water, power and public transport built from scratch, at a cost per dwelling that the government's own strategy describes as many times higher than extending services to an established suburb that already has them. Building up rather than out is also the only realistic way to protect the bushland, hills and nature reserves that ring the city and that most Canberrans say, in the government's own consultation, that they want kept intact.
The government can also point to a genuinely open process behind the missing-middle reform, not a rushed one. DPA-04 went to a dedicated Assembly committee, drew 26 formal submissions from residents' groups, developers, planning professionals and the National Trust, sat through two days of public hearings, and was only approved after the government adopted the committee's recommended tightening on parking and tree canopy — a sequence that took a full nineteen months from Draft Plan Amendment to Major Plan Amendment. On the numbers the government cites, missing-middle housing delivered inside existing suburbs also uses established schools, shops and bus routes rather than requiring new ones, and lets people who want to downsize stay in the suburb where they have lived for decades rather than being pushed to the city's edge. That is a genuine, defensible planning philosophy, and it is shared, in broad terms, by every state and territory government now grappling with the same housing shortfall.
The evidence
Set against that case, the record so far is uneven. The planning system the government built to speed up development has, on its own figures, been slower than it promised: in the six months to 31 December 2024, the median time to assess a "significant" development application reached 117 working days against the system's own 60-day target — 95 per cent longer than planned — and nearly a third of all development application decisions across the system were made outside their statutory timeframes (Canberra Times reporting on ACT planning performance figures, Feb-2025). The directorate has since set up a dedicated Development Solutions unit to unblock the roughly 120 possible steps a single application can pass through, and reports a marked improvement in 2025-26, deciding 742 development applications with 82.8 per cent on time (Canberra Times reporting, Jul-2026) — a genuine gain, though one measured against a system that was missing its own targets by a wide margin only a year earlier.
The amenity side of the ledger is harder for the government still. Canberra's overall urban tree canopy fell from 22.7 per cent in 2020 to 21.8 per cent in 2025, moving away from, not toward, the government's own goal of 30 per cent cover by 2045 — and the decline is concentrated on privately leased residential land, where canopy fell from 21 per cent to 19 per cent over the same five years, against a slight increase on public land (ACT City Services, Urban Tree Canopy Coverage Report, 31-Mar-2025). The ACT Auditor-General's own Report No. 1 of 2024, Urban Tree Management, found the 30 per cent target already in trouble and made eleven recommendations to Transport Canberra and City Services, including a strategic program to identify and replace ageing trees before they are lost (ACT Auditor-General, Report No. 1 of 2024, Feb-2024).
The government's own auditor has twice found that changes made to the Territory Plan — the document that decides what can be built where — were not backed by the analysis the government told the public had been done.
The critique
The missing-middle reform itself survived scrutiny reasonably well: it went through a real committee process, drew real objections, and came out changed by them. The deeper problem is what that process reveals about how this government handles the Territory Plan more broadly, and whether residents are right to distrust the next round of changes on the strength of how the last ones were made. In 2026 the ACT Auditor-General examined how the government altered Territory Plan requirements for the Phillip Swimming and Ice-Skating Centre site, downsizing the planned pool from an outdoor 50-metre facility to a 25-metre indoor one, and found no needs analysis had actually been done to justify the change — even though ministers had approved, and officials had told the public they had commissioned, a "detailed aquatic facility planning study" that was never in fact carried out (ACT Auditor-General, Changes to the Territory Plan requirements for the Phillip pool, 2026, approx.). That finding does not touch housing directly, but it establishes something that does matter to the housing debate: the same government asking residents to trust that missing-middle blocks, heights and setbacks have been carefully calibrated has already been shown, on a different site, to have changed Territory Plan settings first and found the justification for them later, or not at all.
Heritage and amenity groups made a related point about the missing-middle process itself. Submissions from the Reid Residents' Association and the National Trust argued the draft Missing Middle Housing Design Guide leaned on subjective, "opaque" language rather than clear, checkable rules, and pressed for firmer protection of Canberra's handful of heritage-listed garden suburbs — Reid, Ainslie, Griffith and similar precincts built in the 1920s and 1930s on explicitly garden-city principles — rather than a single set of rules applied uniformly across every RZ1 block in the city (submissions to the Standing Committee on Environment and Planning inquiry into DPA-04, 2025-26; National Trust of Australia (ACT)). The tree-canopy numbers give that argument some empirical weight: canopy loss on privately leased land, where missing-middle infill actually happens, is running ahead of loss on public land, in a Territory whose own auditor has already found the tree-planting program insufficient to hit its 2045 target. And the approval-time figures cut against the government's own supply argument — a system that took until 2025-26 to bring "significant" applications close to its stated target means the missing-middle reform's new development rights will translate into new dwellings only as fast as the assessment system that has to process every one of them.
The risk to the future
Every future rezoning inherits the last one's credibility
The ACT government still needs, by its own account, tens of thousands more homes than the missing-middle reform alone will deliver, and the 70/30 infill target set in 2018 assumes further waves of density in established suburbs over the next two decades. Each of those future changes will be judged, fairly or not, against how the last one was handled — and the public record so far gives residents real grounds for scepticism rather than paranoia: an Auditor-General who has twice found Territory Plan decisions were not backed by the analysis the government said stood behind them, a development approval system that spent a full year running at roughly double its own target processing time, and a tree canopy that is shrinking fastest exactly where infill is happening, against a 2045 target the government's own auditor has already flagged as at risk.
None of that means the densification strategy is wrong on the merits — the housing shortfall and the case against endless greenfield sprawl are both real, and the government's response to the Standing Committee's Report 6, due by 30 August 2026, is a concrete near-term test of whether it will keep tightening the safeguards residents asked for. But a planning system that asks Canberrans to accept more change to the streets they live on cannot keep asking them to simply trust that the numbers behind each change have been done properly, when its own watchdog keeps finding, case by case, that they have not. Repairing that credibility — through faster, more reliable approvals and Territory Plan changes that are demonstrably backed by the analysis the government claims — matters as much to whether Canberra gets enough housing as any zoning map does.