As the population of Australia grows, a critical area of challenge for planners revolves around how to limit urban sprawl.

While the CBDs and surrounding 10 kilometres accounted for more than half all of employment growth which took place within metropolitan boundaries across all five of the major Australian capitals between 2006 and 2011, Grattan Institute CEO John Daly says, in each case, more than half of all new dwelling construction took place more than 20 kilometres from the city’s centre.

For those living in many outer suburbs of Sydney, Melbourne and Brisbane, Grattan Institute data shows that more than 90 per cent of employment opportunities within the metropolitan areas of those cities involve daily commutes of 45 minutes or more in each direction.

Combine this along with the often limited availability of public transport options and you have a recipe for longer commuting times, clogged roads, reduced time spent with family, higher levels of spending on road infrastructure requirements and higher levels of carbon emissions.

Long and costly commutes add a further barrier to many who are already in lower income brackets from the point of view of accessing the best and most diverse range of employment options in the city centre. In Melbourne, for instance, a Charting Transport analysis of 2011 Census data indicated that while more than half of all workers from suburbs such as Preston, Footscray and Williamstown worked in the CBD, this was true of less than 10 per cent of those living in some parts of areas such as Melton, Frankston, Cranbourne and Lilydale.

This is especially the case for those with family responsibilities. Many parents no doubt find themselves limited to the more restrictive range of employment options within their localised area as responsibilities associated with activities such as dropping off and collecting children from childcare or primary school mean that long commutes to and from places of employment are not in many cases a realistic or viable option.

Beyond that, the car dependent nature of many outer suburbs and generally restrictive range of social, employment and entertainment options within the local area creates barriers for youth in terms of gaining work or enjoying social activities, with higher rates of youth unemployment and crime a result.

As the widespread nature of some suburbs discourages walking and a combination of longer commuting times and more restrictive offerings in terms of quality fresh food outlets leads to greater consumption of take away food, meanwhile, the growth in outer suburbs through sprawl could be detrimental to public health.

Sprawl also necessitates greater levels of taxpayer investment in providing services such as transport, local roads, water, sewerage, healthcare and schools, as compared to what in some cases may be greater utilisation of existing services in a more dense urban environment (though as Daly points out, retrofitting existing infrastructure which does reach capacity can be extremely costly).

Finally, sprawl can eat into green wedges and productive agricultural land. For example, a University of Western Sydney study in 2013 found that 97 per cent of fruit and vegetables being sold though the Sydney Markets at Flemington which serves restaurants, greengrocers and supermarkets was sourced from more than 150 kilometres away, with local produce largely having been wiped out as new housing eats up unprotected farmland.

For all of these reasons, while many no doubt enjoy outer urban living and the space and greater proximity to nature that it offers, planners and economists generally agree on the need to limit any form of uncontrolled outward urban expansion.

“There are lots of good reasons to tackle sprawl,” Planning Institute of Australia (Victoria branch) president James Larmour-Reed said.

“It doesn’t mean that living in a suburban environment is not legitimately an attractive option – that’s not what I am saying. What I am saying is that we need a greater diversity in our cities so that we don’t need to continue to have that (sprawl) as the main form of new construction. It (sprawl) can’t be the only way that we tackle population growth.”

Griffith University Professor of Urban Management and Planning Paul Burton agrees.

“If you mean relatively low density housing, construction on the fringes of our cities with little social infrastructure like schools or hospitals and very limited local job opportunities and little or no public transport, then in my view, it’s something that we should avoid,” he said.

In terms of what can be done, commentators invariably point not only to opportunities for further infill in inner urban areas. This often comes through high-rise developments but also to a greater diversity of medium density housing options within the middle suburbs, including subdivisions, townhouses, detached units and low rise apartments, with intensive development in and around critical transport links.

Burton says the debate thus far has revolved around a polarised model of choice involving either new high-rise apartments in the city or new single detached housing on greenfield development sites. Going forward, he would like to see an end to the phenomenon of largely single-storey housing going throughout the suburbs right up to a sudden jump to high-rise on CBD fringes and instead see a greater range of low-rise multi-residential dwellings throughout the middle and inner suburbs.

Daly agrees, noting that Grattan Institute research had demonstrated considerable levels of desire for medium density housing in the middle ring but adding that developments in these areas were largely being held back by convoluted planning and appeals processes. Daly says the problem is not so much sprawl in itself but rather a failure to create sufficient volumes of new living options closer in to the CBD.

“We are creating over half the jobs in the CBD and the ten kilometres around it of the five big cities,” he said. “But on the other hand, more than half of the accommodation we have created in those cities is being created more than 20 kilometres from the city centre.

“So the problem I would argue is not with sprawl per se. The problem is a failure to create more housing where the jobs are and where the jobs are likely to be (going forward).”

Beyond greater levels of infill, an interesting area of debate revolves around the notion of decentralisation or poly-centralisation of cities involving ‘clusters’ of employment, retail and residential opportunities. These would ideally be situated around transport links with strong levels of amenity and good transport links with the CBD and with each other.

To a degree, employment clusters already exist. In Melbourne, for example, around 58,500 people work at an education, research and industry hub centered around Monash University in the south-east. Further out, another 55,000 work at a manufacturing, health, education, wholesale retail, postal service and warehouse hub at Dandenong South, while a healthcare, professional and technical hub at Parkville in the inner north supports a further 32,700. More are planned at LaTrobe in the city’s north and East Werribee and Sunshine in the west.

Should more of these types of developments succeed, Burton says the payoff would be significant. Once gaining critical mass, these could support a good range of amenities such as cafes. They would also support only investment in transport to and from the cluster but also localised bus services within their immediate vicinity. Most importantly, these areas would provide valuable employment opportunities for those living in middle and outer suburbs without the need for stressful and arduous commutes into the city centre.

Daly agrees that these would be worthwhile, but cautions that these have been talked about and tried and that we need to be realistic about the fact that the biggest area of employment creation in a service oriented economy will not be in these clusters but rather in the city centre where business can be close to their clients.

“It makes total sense to try to plan the centre of Werribee or Sunshine so that whatever employment is there is clustered together, it is reasonably easy to get to and that it is nicely designed,” Daly said. “And of course, we don’t want to discourage employment in those areas.

“But we need to be realistic about the mini-cities. The dominant source of employment growth is going to be in the CBD and the areas immediately around it, and it is worth remembering that all capital cities have had some kind of polycentric plan in the last decades.

“This is not new (the idea of polycentric cities) – it’s old. We have 20 years of government plans for these cities to grow much faster than the CBD. We have 20 years of abject failure.”

Beyond urban clusters, there are regional centres, such as Wollongong, Newcastle, Geelong, Ballarat and Bendigo. Larmour-Reed says those with good links to major cities offer significant potential for housing and for employment, especially where there is a collaborative approach between business, local government and the tertiary sector in order to attract critical mass, high quality jobs and high amenity. He says Bendigo in central Victoria is a good example, where road and rail links to and from Melbourne have been upgraded and they have made the city centre an attractive and vibrant place for tourism, retail and offices. There is also a vibrant campus at LaTrobe University and the Bendigo Bank which is headquartered there is doing excellent things in the community.

Burton agrees that regional cities have promise but cautions that you they should not grow too fast, lest some of their character and appeal be jeopardised. Daly, meanwhile, cautions that while those within two hours’ drive of major capitals are generally growing, the same cannot be said of others in more remote areas such as Mildura, which at best are merely pulling in people from the nearby countryside.

Finally, Larmour-Reed says it is important not to ignore the potential of brownfield urban infill sites. Speaking particularly of Melbourne, he says the city has a lot of industrial land in the west which is within the existing boundaries of the city and is no longer being used for industrial purposes. Such land could easily be cleaned up and used for residential purposes, he said.

As our population continues to expand, limiting urban sprawl in Australia will become increasingly challenging.

With the adoption of a few sensible strategies, we may well be able to make substantial inroads in this area.