Sweet spot: Sustainable midrise for healthy, nature-positive communities

An alternative to both highrise living and urban sprawl, well-designed medium density is the way to go for balancing the needs of people and nature, says ecologist Sarah Bekessy.

We are hearing a lot at the moment about how to solve Australia’s housing crisis, with some saying we should focus on releasing land to allow for low-density urban fringe developments and others arguing for high-density highrise in established suburbs. But there is another option that is rarely discussed: sustainable midrise, which can be better for people and nature alike.

The negative impacts of urban sprawl on communities are well established: high transport and household energy costs, susceptibility to household financial stress, high infrastructure costs, significant impact on the natural environment, low walkability, poor access to open space, and conflicts with food production. On the flip side, high-density highrise environments exacerbate the urban heat island effect and are typified by low walkability and inactive streetscapes – and residents experience social isolation and poor access to open space.

Neither approach is good at providing access to nature or for protecting and enhancing biodiversity. Highrise living can lead to a disconnection from nature and streetscapes, and the production of construction materials such as concrete and steel has huge negative impacts on nature. A recent study published in the Society for Conservation Biology’s journal Conservation Letters found that the construction industry in Australia contributes more than a quarter of the species extinction risk caused by supply chains.

While the dream of urban fringe living is often sold as the opportunity to enjoy a big backyard and plenty of open space, the reality is that houses often almost fill blocks with minimal space for a garden and limited access to parks and nature. Research such as the 2019 study by Kroen et al. published in the Journal of Transport & Health shows that residents often spend so long commuting that there is little time to visit parks anyway.

Furthermore, urban sprawl frequently overlaps with some of our most critically endangered species and ecosystems. For example, less than one percent remains of Melbourne’s basalt plains grasslands, a habitat that is absolutely filled with critically endangered species like the recently rediscovered grassland earless dragon – and yet it is still being cleared for housing. In Perth, the Swan Coastal Plain is a world biodiversity hotspot, yet we have cleared hundreds of thousands of hectares of this rare ecosystem for housing over the last few decades. The Cumberland Plain woodland is one of Australia’s most threatened ecosystems and home to Sydney’s largest population of koalas, yet it’s where we are growing Western Sydney. Similar stories can be told for most cities and regional centres across Australia.

It’s a little-known fact that cities in Australia are hotspots for threatened species, as described in studies such as Ives et al. (2016), which found that cities support 30 per cent of our threatened species (including 46 per cent of our threatened animals). Some threatened species – about 40 – exist only in urban areas, and so depend entirely on activities within cities for their protection. Researchers including Soanes and Lentini (2019) conclude that they are likely to disappear without special effort from us. Many others rely on cities for habitat and resources that we can provide in parks, streetscapes and backyards.

While ‘offsetting’ by protecting or planting areas elsewhere is often used to justify the clearing of critically endangered habitats for urban development, successive reviews have shown that this doesn’t work for biodiversity. This is because it is very difficult to recreate whole ecosystems or to move species to different locations. Putting a fence around a patch of habitat far outside the city while we clear nature for housing is a failed approach, as it doesn’t result in biodiversity gains and it takes nature away from people in cities who could otherwise benefit from engaging with it. Further, we all know that nature has place-based values that are irreplaceable.

The Biodiversity Council has created a pledge for developers, investors and certifiers, encouraging them to commit to ending the clearing of habitat for threatened species and shift towards nature-positive approaches for development; read more at naturepledge.org.au.

A better approach: The sustainable midrise model

If you’ve ever visited European cities like Barcelona or Berlin, you will be familiar with the model of housing I’m talking about as a better solution for nature-positive development.

Sustainable midrise refers to housing between four and seven or so stories, a height range that has been shown to improve accessibility and connectedness to streets and nature. In the best examples, streetscapes are more active, with a mix of residential, commercial and office spaces at ground floor level and a diversity of high-quality building typologies to ensure dwellings for a range of urban residents, including families.

Access to open space is critical, with opportunities for semi-private courtyards as well as larger public parks nearby. I lived in an apartment block just like this in Leipzig, Germany, when my daughter was a baby. We used to enjoy meeting up with the other parents in the building in the evenings for a chat (and sometimes a gin and tonic) while the kids played together in the courtyard.

Benefits of sustainable midrise

Sustainable midrise can achieve high housing densities while delivering benefits to human health and wellbeing. Developing on land that is already cleared and using approaches that are regenerative for nature such as biodiversity-sensitive urban design can help bring nature back into the urban fabric, enhancing habitat for target species and providing residents with regular access to green spaces. My colleagues and I explore this in our 2024 article in Conservation Biology, ‘Designing cities for everyday nature’. Use of sustainable construction materials can further reduce the negative impacts of housing developments on nature.

There are multiple health benefits of living in sustainable midrise designed with biodiversity in mind, including improvements to physical and mental health delivered through contact with nature, reduction in loneliness and social isolation through urban design that encourages vibrant communities, and proximity to amenities and public transport, which reduces travel times. One study by the UK’s Office of National Statistics found that with every additional minute of travel to work, our happiness measurably decreases!

Finally, consolidating our cities rather than allowing endless urban sprawl can save governments money through reduction in infrastructure costs; Infrastructure Victoria recently determined that the state would be $43 billion better off by 2056 if it swapped out urban sprawl for compact design like sustainable midrise.

What you can do
While we don’t typically think much about plants and animals when buying, building or renovating a house, it could be one of the most important ways that you can personally help reverse the biodiversity extinction crisis. If you’re buying a block, try to choose one that has not recently been cleared, as it’s quite likely to be home to at least a couple of threatened species. If you can buy into sustainable midrise built on land cleared long ago, you will probably find it more affordable upfront and in the long run, with reduced energy bills and transport costs. You can, of course, also encourage your building designer or architect to select nature-friendly building materials, and ask garden designers to think about wildlife-friendly options including diverse native vegetation, water, rocks and logs (see my article ‘Nurturing nature: Designing a home with biodiversity in mind’ in Sanctuary 50 for more on this).

In our rush to build much-needed new housing, it would be a great shame to mow down the last patches of habitat for endangered plants and animals in our cities, especially when alternatives like sustainable midrise exist. It’s entirely possible (and desirable) to build housing that is regenerative for nature, rather than accepting its inevitable demise. Sustainable midrise is better for the environment, for the economic bottom line and for thriving, healthy communities.