As councils look to increase housing supply without adding more sprawl, rooftops are emerging as an untapped opportunity.
Walk through almost any Australian centre and look up, you will see thousands
of flat roofs doing very little, a few plant rooms, some air-conditioning units, maybe a sign or two, and a lot of empty space.
At the same time, councils are under pressure from every direction. Residents want housing they can afford, communities want less sprawl and traffic, businesses want footfall and a strong local economy, governments want faster approvals, and everyone wants lower emissions.
Rooftop housing through ‘airspace development’ will not solve the housing crisis alone, but it is one of the rare options that can add homes without new land, new roads, or pushing the city further out.
It can also help refresh older buildings, bring people closer to services, and cut carbon by reusing what we already have.
The missing link is not the crane or the construction method. It is the local pathway. That is where councils make the difference between a good idea and a real housing pipeline.
Why building ‘up’ is different
Traditional housing supply starts with land, then roads, then services, then years of planning and delivery.
Rooftop housing starts with something already paid for: the building frame, the access to transport, and the services in the street. When extra homes go on top of an existing site, new residents can often ‘share’ what is already there: water, sewer, power connections, footpaths, public transport, and local shops.
There is also a clear carbon case for reuse. Infrastructure Australia noted that embodied carbon from building activity is a meaningful share of national emissions, and that ‘upfront’ emissions are locked in once a building is built. Cutting those emissions delivers immediate benefits. Reuse also tends to reduce whole-of-life impacts compared with demolition and rebuilding, especially when performance is comparable.
This has been proven to work in Australia. Melbourne’s 55 Southbank Boulevard added ten levels using cross-laminated timber above an existing building, creating significant additional space and becoming a well-known local example of vertical extension.
Overseas, cities are treating rooftops as a city-wide resource. Rotterdam has highlighted the scale of its flat-roof opportunity (often cited as about 18.5 square kilometres) and is actively promoting ‘multifunctional roofs’ for outcomes such as water retention, energy, green space and public value.
The biggest barrier is not engineering. It is the process.
Most rooftop projects die in the mess between ‘possible’ and ‘approved’.
Even where the design is suitable, councils face the same hard questions:
- Has this been demonstrated elsewhere?
- Will neighbours lose light or privacy?
- Will the streets cope during construction?
- Who pays for lift upgrades, fire upgrades, or services?
- Will this create better places, or just more boxes?
None of these are reasons to stop. They are reasons to set clear rules.
The UK experience is useful here, not because Australia should copy it line-by-line, but because it shows how a clearer pathway reduces delay. England introduced permitted development rights for some upward extensions, using a ‘prior approval’ approach where councils focus on specific impacts and quality checks.
Australia can take the same lesson: make rooftop housing predictable when it meets clear standards.
What councils can do
State targets are important. National building rules matter too. But councils control the daily reality: local planning rules, assessment priorities, design expectations, and community trust.
Here is a practical council playbook:
1. Map the opportunity and publish it
Councils do not need perfect data to start. They can build a simple ‘rooftop opportunity map’ using existing information: building footprints, heights, heritage layers, strata areas, proximity to centres and transport, and council asset registers.
Even a first-pass map helps industry focus on the right sites. It reduces speculative proposals, saves staff time and it signals that the council is open to the right kind of projects.
If NSW can point to a clear pipeline near centres and stations (its Low and Mid-Rise Housing Policy targets up to 112,000 homes over five years, around 171 town centres and stations), councils elsewhere can also define their local rooftop pipeline with confidence.
2. Create a ‘good roof extension’ rule set
Most community concern comes from uncertainty. Councils can reduce conflict by setting clear pass/fail expectations upfront, including:
- Setbacks and step-backs from street edges
- Limits on overlooking and privacy impacts
- Daylight protection rules
- Noise and construction-hour conditions
- Clear requirements for landscaping, green roofs, and heat reduction
This is classic council work: turning broad goals into practical rules.
3. Set up a fast lane for compliant projects
Councils don’t need to approve “anything”. They need to approve the right things faster.
A fast lane could mean:
- A dedicated assessment pathway for rooftop proposals that meet pre-set criteria
- Shorter assessment timeframes for compliant projects
- Standard conditions and templates to reduce back-and-forth
This approach is common in other planning reforms, including programs designed to accelerate assessments while keeping proper checks.
4. Require a fair ‘share of benefits’ for the existing building and the neighbourhood
Rooftop housing should not feel like something being ‘done to’ a building or a street. It should feel like an upgrade.
Councils can encourage benefit-sharing arrangements such as:
- Lift upgrades and accessibility improvements
- Solar and energy upgrades that reduce bills for existing residents
- Waterproofing and façade repairs funded by the new development value
- Public value outcomes where appropriate (shade, greening, safer streets, better frontage)
This is where rooftop housing links directly to community wellbeing. Better buildings, cooler roofs, more walkable centres, more customers for small businesses, and more residents close to services.
5. Start with council-owned sites to prove the model
Councils own car parks, depots, libraries, community centres, and administrative buildings. Not all are suitable, but some will be.
A small pilot on council sites can:
- Demonstrate construction staging with minimal disruption
- Create a template for design quality and community engagement
- Attract credible builders and financiers
- Build public confidence
Once residents see one good project, the conversation changes.
Market signals already point to scale. Commercial Real Estate Services has described residential airspace as a major opportunity in Australia and has discussed the UK’s large airspace market and approval volumes as evidence of maturity overseas.
But the point is not the headline number. The point is that industry interest exists, and councils can either shape it early, towards quality and public value, or deal with it later, as unpredictable one-off proposals.
A practical next step: a 12-month council action plan
Within a year, any council could aim to deliver:
- A published rooftop opportunity map (even if staged)
- A clear local ‘good roof extension’ guide
- A defined fast lane for compliant proposals
- One pilot site (council-owned or partner-owned) moving into delivery
The bigger goal: housing supply and better places
Rooftop housing is not just a supply tool. Done well, it is a city-shaping tool.
It can add homes where people already want to live. It can reduce long commutes. It can bring life back to centres after hours. It can fund upgrades to ageing buildings. And it can cut carbon by reusing structures instead of starting from scratch.
Councils are not a ‘step’ in this transition. They are the enablers.
If we want more housing without more sprawl, we need to treat rooftops as part of the solution, not as an exception, not as a special favour. It’s normal city-building, just one level higher.
