In cities across the country, the promotion of higher residential densities in certain areas has become an orthodox part of urban planning. Consolidation, as opposed to sprawl, is seen as a way to accommodate the apparent inevitability of larger cities in a more sustainable, economical, and healthy way.
But the advantages are not always entirely clear-cut. There is still debate, for example, over whether high density automatically cuts greenhouse emissions and is generally more sustainable.
One of the other great touted benefits of high-density living is that it frees people from cars and gets them active. But is there a direct link between higher-density neighbourhoods and health?
Heart health and density
We do know there is a relationship between the built environment and behaviours beneficial to health. Physical activity is one such behaviour, and when done regularly can reduce cardiovascular disease-related deaths by up to 35%.
Recognising this link, the Heart Foundation has long advocated for walkable neighbourhoods with mixed land use and densities, connected streets, quality open spaces, and access to public transport.
It takes many factors to create a “walkable neighbourhood”. But how does residential density specifically influence opportunities for physical activity? Our research concludes that the effect of density on active living is incredibly complex. To unpick it, let’s look at how urban planning more generally can influence physical activity.
Good planning and active people
One way to influence activity is to encourage people to use “active transport”, including walking, cycling, and public transport. Good planning can help make these options safe, comfortable and accessible.
Another key aspect is distance. Grid-like street networks with short blocks can make travel routes more direct, but if destinations, like work and home, are too far apart, most people won’t walk or ride between them.
Finally, we need to make sure that people have somewhere to walk and cycle to, and places to engage in more structured physical activity. This normally means mixed-use zoning so that residential areas are interspersed with shops, services, schools and green open spaces.
All this means that higher housing density alone will not make people more or less active. There is, however, certainly a relationship between higher-density built environments and physical activity.
On the surface, a certain amount of density might be quite good for you. This is related to the concept of “critical mass” – the aspects of the built environment that can encourage healthier habits often require people, and sometimes a lot of people, to make them viable. Public transport networks, walking and cycling infrastructure, well-maintained green spaces and small neighbourhood shopping centres all need people to make them work. Of course, they are also easier to provide when less land is taken up by homes.
But it’s not quite as simple as that. While living in low-density areas is linked to lower levels of physical activity, there is also evidence that too much density is associated with negative health outcomes, particularly in terms of mental health. Higher-density can breed stress and social isolation, often associated with depression and anxiety disorders.
Badly constructed or poorly located higher-density housing can also cause problems through poor ventilation and insulation, lack of sunlight, insufficient public and private open space, and exposure to pollutants or intrusive noise.
These issues can lead to respiratory health problems, as well as isolation, fear of crime, and community dislocation. They can very quickly erode or prevent the development of the healthy aspects of higher-density living, including regular physical activity.
So what makes density work?
There are potential health benefits associated with higher-density living, but these benefits depend on several other variables. A review commissioned by the Heart Foundation identified three key factors.
First is the quality of infrastructure in the surrounding neighbourhood and region. Higher-density housing needs to be situated among public transport networks, jobs, schools, shops, services, open space and active transport infrastructure.
Second is the quality of construction and management of the homes themselves. It has been far too easy in Australia to provide higher-density housing that is poorly sited, badly built, and ineptly managed. It is also far too easy to forget that density means diversity – it includes detached and semi-detached housing, townhouses, low- and mid-rise apartment buildings, as well as high-rise.
Third is the social and cultural make-up of the community that is living in higher-density places. We mentioned that healthy built environments need people to make them work, and people are sometimes frustratingly brilliant in their diversity. Indeed, success depends on the capacity of new and existing communities to adapt to different ways of living, working, travelling and socialising. This makes it difficult to make realistic generalisations about the impact of density on human health.
What we do know is that vulnerable populations will be more susceptible to any negative impacts of higher density.
There is evidence, for example, that high-rise living in particular is associated with lower levels of satisfaction and a poorer sense of community in older adults. The needs of children in higher-density housing also deserve special attention.
The issue is a complex one. There are potential health benefits on offer from urban densification, but also the possibility of unintended consequences that can quickly undermine them. As Australia’s cities become increasingly crowded, we will need to watch carefully to know whether we are getting it right.
This article was co-authored by Michelle Daley, Senior Manager, Active Living, at the National Heart Foundation of Australia.
Jennifer Kent does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.