Ever found a bare-nosed wombat napping under your house or heard a possum thumping around in your roof?
You’re not alone. Data from Wildlife Victoria reveals that about 2,400 native animals were reported by people as being in, on or under buildings over the past decade.
For our new study, we analysed these reports to find out which animals were taking up residence in buildings, which parts of dwellings they occupied and what they were doing there.
We uncovered 36 native species that either nest, forage or sleep in our homes, ranging from microbats sleeping in curtains to pacific black ducks nesting on balconies. These encounters show buildings have become de facto habitat for many animals with whom we share our cities.
As Australia races to build more houses, we must design them with at-risk animals in mind. Their survival may depend on it.
Unexpected residents
Our new research reveals wildlife use almost every part of buildings.
Building cavities are the most popular option, with 40% of studied species taking up residence between walls. We found 19% of animals in shelters and structures such as garages and 16% in external surfaces such as eaves, balconies and tops of roofs.
About 10% of animals were found living in interior rooms like bedrooms and kitchens, 9% in spaces under houses and 6% in utility services such as heaters and air conditioners.
These building features often serve similar functions to natural habitats. Roof and wall cavities replicate the conditions of tree hollows. Spaces under houses resemble sheltered ground or burrows. Balconies provide elevated ledges that act as cliff edges. Aircon and water heaters can become ideal microclimates for reptiles.
A mother and baby possum hiding in the roof of a shed.Pleio/Getty
The habitat gap
Buildings are becoming increasingly important for conservation, as natural habitats rapidly disappear from our urban landscapes.
Natural features such as tree hollows – on which more than 300 Australian native species depend – can take centuries to form. Research shows the number of large, hollow-bearing trees in urban areas is declining. And replacement saplings won’t grow and provide habitat for a very long time.
Relying on buildings for habitat is precarious. A renovation or repair can erase it overnight. Exclusion – using physical barriers or devices to keep wildlife out of buildings – may be necessary if an animal poses a genuine health, safety or welfare risk. This is best done by an expert wildlife carer.
The problem is not exclusion itself. Rather, it is the act of excluding an animal and removing its shelter without considering other safe alternatives. This approach will only exacerbate Australia’s extinction crisis.
Our research suggests there’s another largely overlooked way to protect our most vulnerable animals: adapting our houses.
Pacific black ducks are one species that may take up residence in your home.WadeMachin/Getty
Homes as habitat
Australia has a national target to build 1.2 million homes over the next five years.
Constructing a new home involves making many decisions, from where roof cavities will go to whether precious soil is concreted over. Together, these choices shape whole neighbourhoods, including whether they contain vital habitat or force local species to go elsewhere.
Meanwhile, Australia is strengthening standards around the energy efficiency of houses. For example, new builds must be properly sealed to limit air leaks, which account for between 15–25% of heat lost from homes in winter.
However, an energy-efficient home does not need to be a wildlife-free place. Habitat features can be weaved into house designs.
In Scotland, regulations require new buildings to have “swift bricks”, a type of nest box that can be installed in external walls as habitat for the common swift (Apus apus) population.
In Germany’s Brantstrasse building, designers have included swift bricks, bat boxes and hedgehog nest boxes in the actual structure. These approaches show adapting buildings for wildlife can be easy and effective.
Australia currently has no such policy. But several grassroots initiatives are emerging such as wildhouses, where builders fund one standalone bird, bat or glider nest box for every building they construct.
Urban designers and planners are increasingly designing cities with wildlife in mind. This approach, known as biodiversity sensitive urban design, aims to construct urban environments that minimise threats to plants and animals while accommodating their resource needs.
For example, a new suburb may decide to plant flowering meadows instead of lawn in streetscapes and parks. Both Canberra and Adelaide have adopted this approach in policy.
Where to from here?
Adapting buildings for wildlife must be based on robust ecological research. Certain features such as bird spikes, netting and reflective glass are designed to keep wildlife out. This so-called “hostile architecture” can wound and even kill animals.
In some cities, the design of buildings may favour a handful of urban-adapted species. In Melbourne, for example, a lack of suitable habitat for smaller forest birds such as fairy wrens and yellow robins means they are rapidly being pushed out by aggressive noisy miners.
Cities should not be places where concrete simply replaces nature. Research suggests urban areas will become increasingly important to tackling the extinction crisis. Australia urgently needs more homes. But in our rush to build them, we must not neglect the needs of the vulnerable animals that may have nowhere else to go.
Sarah Bekessy receives funding from the Australian Research Council, the National Health and Medical Research Council and the European Commission. She is a Lead Councillor with The Biodiversity Council, a member of the World Wildlife Fund Eminent Scientists Group and an advisor to ELM Responsible Investments, the Living Building Challenge and Wood for Good.
Bethany Kiss does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
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China’s carbon dioxide emissions fell by 1% after the outbreak of the US-Israeli war on Iran, thanks to a sharp reduction in oil consumption and a steady rise in the use of electric vehicles and public transport, analysis shows.
The report reveals the role of clean energy in cushioning the price shocks caused by the strait of Hormuz crisis to the world’s biggest oil importer. It also reinforces hopes that China, which is the world’s biggest greenhouse gas emitter, may be nearing a turning point in decarbonising its economy.
Conservationists hope koalas will start using the first koala underpass south of Sydney despite research suggesting the native animal rarely uses them.
There are fears out-of-control rabbits and the unexpected holes they keep adding to the greens will threaten the legacy of one of the oldest golf courses in Western Australia.
Many Australian homes were not built to cope with a rapidly changing climate.
Compared to new homes, established houses tend to consume – and waste – significant amounts of energy.
That’s where home energy upgrade programs come in. These programs help households boost the energy efficiency of their houses while cutting power costs, emissions and grid demand. They are mainly run by state and federal governments, but community-led programs are multiplying across Australia.
However, our recent research shows not all Australians can currently benefit from these programs. Let’s unpack why.
Top down or bottom up
In Australia, home energy upgrade programs are largely developed and delivered by state, territory and federal governments. These programs assume that if households are given the right information and a financial incentive, they will decide to upgrade. This approach allows them to reach large numbers of people, with Victoria’s scheme alone delivering more than 180,000 upgrades to households in 2025.
However, government-run programs tend to benefit households that can pay the residual cost of upgrades, are motivated to change and have the skills to navigate any practical or legal hurdles. This is because energy upgrades can be costly and complex to install.
Community-led programs are gaining traction in Australia. These programs – run by either communities or local government – are often much more attuned to what residents want and worry about. They are built on trust and relationships, and provide practical advice and hands-on support. These are often what so-called “hard-to-reach” households – such as renters, low-income Australians and people from culturally and linguistically diverse backgrounds – need most. Without such supports, these households tend to miss out.
One organiser told us:
“Developing a trustworthy relationship with the household is just key. Otherwise, you get very low uptake of these programs.”
Upgrading a house can involve making lots of complex decisions. Many local home energy upgrade programs are resource-poor and may have to rely on state or federal schemes, which are often difficult to navigate and apply for. This is particularly true for people whose first language is not English or who lack computer skills.
Research consistently shows trusted relationships make upgrading much smoother. They are also key to ensuring locally-led home energy upgrade programs actually work.
To cultivate such relationships, program managers must create opportunities for householders to interact with each other. This could be community forums, appliance demonstration events or open home days where people explain how they upgraded their home and what the results were.
We interviewed 19 people who design and deliver these programs, working in state government, local government, community groups, peak bodies and consultancies. Most were based in Victoria, with participants also in New South Wales and Queensland, and several working nationally.
A common theme was the value of “social work” in the delivery of home energy upgrade programs. Examples of social work include helping people identify which incentives they are eligible for or guiding them through the application process. Householders may also need help picking the right upgrade products for their home and finding tradies who can safely and effectively install them.
One organiser acknowledged:
“I really had to hold people’s hand through a lot of it, which is fine if you’re expecting that.”
Another organiser shared:
“The solar installer that we had, they obviously don’t work with a lot of low-income people because they can’t afford the solar. They weren’t used to working with that type of audience with all of these extra layers of needs.”
One issue is many locally-led home energy upgrade programs don’t have the funding or resources to last. But we can change that by:
recognising councils and community organisations as delivery partners in their own right, with a clear role in designing programs and funding that covers dedicated staff
offering more predictable, sustainable funding to give program managers the time to establish relationships with householders and build on long-term projects
rethinking how we measure success, by evaluating whether programs build trusted relationships and not just the number of upgrades installed or rebates claimed
creating ways to share knowledge between local programs by supporting initiatives that connect councils and community groups.
Locally-led home energy upgrade programs are popping up across the country. Our research team is building a platform to give organisers the tools and guidance they need. But to ensure these programs reach all Australian homes, we must recognise and fund them as a critical part of our nation’s clean energy transition.
Christoph Brodnik receives funding for this research as part of the Energy Upgrades for Australian Homes project, which is led by Monash University and funded through the RACE for 2030 Cooperative Research Centre.
