Has spare infrastructure capacity in the inner city disappeared?

Guess what this architectural gem in Stockholm is? Click to find out.

The received wisdom is it costs much less to provide infrastructure for an inner suburban dwelling than for one in the outer suburbs. However, as I noted last time, we don’t know how big the difference is or even, for that matter, if it’s positive or negative – we simply lack reliable evidence.

There are reasons, however, to suspect the savings in infrastructure outlays associated with urban consolidation might be much less than is widely thought. It’s plausible that the popular claim of an $85,000 per dwelling saving could be well off the mark (note I’m only talking in this post about the capital cost of infrastructure, not the economic costs and benefits of a fringe vs central location).

From the time urban consolidation was first seriously put on the table in Australia as a policy option, a key premise was the availability of ‘spare’ infrastructure capacity in the inner city. This part of the city had previously supported larger working class and migrant populations, so there was ‘free’ infrastructure to be had in support of a restoration of earlier population levels.

There’s not much sense in assuming any capacity is free (it all has to be paid for) but looking from the perspective of 2011, there are reasons to question if there actually is any spare physical capacity left, at least in relation to some types of infrastructure.

A key reason is a lot of whatever spare infrastructure capacity existed has already been used up by gentrification. At the 2006 Census, there were 36,488 more residents in the inner city of Melbourne than there were in 1976 (and 76,422 more than when the inner city was at its lowest ebb in 1991). In fact of the 31 municipalities in metropolitan Melbourne, only the City of Moreland and the adjacent City of Darebin had significantly fewer residents in 2006 than in 1976 – Moreland had 14,585 fewer and Darebin 17,137 fewer. That is not a lot in the context of projections Melbourne will grow from a current population of four million to seven million by circa 2049.

Even where there are fewer residents today than in the past, they might still have a much larger “infrastructure footprint” than their predecessors. Modern households have many more resource-intensive devices like flat panel TVs, air conditioners, heaters, computers, spas, and so on, than their predecessors. They have more cars than former residents, so there’s less room for parking. They also have higher standards – the primary school that used to accommodate 300 kids in six or seven classrooms now has to build twelve to handle the same enrolment.

Moreover, households today are smaller on average, so they have fewer ‘economies of scale’ in resource consumption than earlier generations. Two households of three persons each use more gas for heating than they would if the same six residents shared a single dwelling. Gentrifying households are also wealthier on average than the sorts of households who used to live in the inner city and inner suburbs 30 to 40 years ago. On a per capita basis, wealthier households consume more of just about everything worth having. Again, that will require more infrastructure capacity.

Thus it’s possible infrastructure in some locations could be at or above capacity even with a much lower population than those places housed in the 1970s. Read the rest of this entry »

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Are infrastructure costs higher on the fringe?

Capital costs per dwelling of infrastructure provision - inner suburbs vs outer suburbs (from Trubka et al)

The exhibit above purports to show that the cost of infrastructure associated with building a new dwelling within 10 km of the CBD of a city like Melbourne is, on average, $50,503. In contrast, it costs $136,401 to provide infrastructure for an outer suburban dwelling i.e. located more than 40 km from the CBD. That’s a huge difference: $85,538 per dwelling.

The figures come from a 2007 report, Assessing the costs of alternative development paths in Australian cities, written by three Curtin University academics, Roman Trubka, Peter Newman and Darren Bilsborough. I’ve mentioned this report before, but that was primarily in the context of The Age and some public sector agencies tending to conflate economic costs with infrastructure outlays (they’re not the same!).

The figures above however are solely infrastructure outlays (not economic costs). Judging by the extent to which Trubka et al’s report is cited by government agencies, there appears to be strong demand for this type of information. It seems, however, that these are the only numbers on this topic around. That’s unfortunate because they have some very serious shortcomings as an indicator of the relative cost of providing infrastructure in inner and outer locations.

The key deficiencies are they’re old; they don’t relate to Melbourne; and they’re not transparent. Trubka et al sourced them from a 2001 report, Future Perth, prepared by the WA Planning Commission to assess infrastructure costs in Perth. Future Perth didn’t calculate its estimates from first principles but rather surveyed 22 earlier studies, some dating from as far back as 1972 and some relating to costs in the USA and Canada.

Future Perth is a working paper and hasn’t been published – hence the rigour of its methodology and those of the 22 studies it drew from hasn’t been tested. Unfortunately, Trubka et al provide scant explanation of their infrastructure estimates, relying instead on a reference to Future Perth.

I can’t say for sure the Trubka et al estimates are wrong, but I can say they’re unlikely to be right. I can also say they’re far too flaky to be relied upon to guide significant policy or investment decisions here in Melbourne. There’s clearly a demand for this sort of information so it would be sensible for the State Government to undertake its own rigorous and up-to-date assessment of the costs of metropolitan infrastructure provision.

Although not as decisive as the shortcomings discussed above, I also have some issues with how Trubka et al have set up their cost comparison. Actually, because the report doesn’t elaborate much on the various infrastructure items, I’ll treat these as questions, or areas that need clarification. Read the rest of this entry »


Is inner city living the solution to obesity?

How much exercise is needed to burn off food?

It’s often pointed out that residents of the inner city, on average, are less obese than residents of the outer suburbs. Since the inner city is denser, more walkable and has much better public transport access than any other part of the metropolitan area, the conclusion seems obvious to many – a key strategy to address obesity should be to encourage higher dwelling densities and better public transport in the suburbs, especially the newer, fringe areas.

The flaw in this thinking is it fails to observe that the inner city – defined roughly as the area within 5 km of the CBD – is a different world. Relative to the suburbs, the inner city has an emphatic over-representation of younger, well educated and affluent residents with fewer dependents. The proportion of the population made up of young singles is three times that of the metropolitan area as a whole and there are twice as many young couples without children.

These are the sorts of people who on average are slimmer because they’re younger, who are of an age where appearance is enormously important, and who are well educated enough to know about nutrition and eschew fast food. They can afford to buy high quality fruit and vegetables and pay for gym memberships. Because they’re more affluent, they have fewer children on average and hence less need for a car.

They live in smaller dwellings so they can be near the CBD and take advantage of its enormous and unparalleled concentration of high-paying professional jobs, its matchless endowment of cultural attractions and its huge and diverse range of social and entertainment opportunities. There’s no other concentration of activity within the metropolitan area that comes even close to the richness of what the inner city offers.

Because they live at higher density, driving is too hard for many trips – roads are congested and parking costs range from expensive to impossible. So residents often walk or use public transport instead. That’s O.K., because they happen to live in that transit-rich, small and unique geographical area where every train line and tram line in the entire metropolitan area – the result of 130 years of construction and at least one spectacular land boom – converges.

So population density and access to public transport are not the underlying forces driving this group’s superior average BMI. Rather, it’s a combination of the small but highly specialised group who can afford to live there, on the one hand, and the special characteristics of the area, particularly the presence of the CBD, on the other.

It’s pie in the sky to imagine the sheer scale and complexity of the highly specialised attributes offered by the inner city could be replicated in the suburbs – much less the outer suburbs – within the foreseeable future. The inner city is focussed on the CBD and in almost every city in the world, the number of jobs in the city centre is an order of magnitude larger than any suburban centre (Atlanta is possibly the sole exception). In Australia, the centre offers the cream of corporate jobs.

The importance of proximity to the CBD in explaining the special character of the inner city is demonstrated by the fact walking’s share of work trips plummets from 13% in the inner city to just 2% immediately one locates in the adjacent inner suburbs. This share is only marginally better than the outer suburbs.

Will building at higher densities and providing better public transport in the outer suburbs significantly lower the incidence of obesity? Not likely. Even if all outer suburban dwellings were townhouses, the incentive to walk is much lower if there’s no CBD, cultural precinct, river, beach, historic buildings, hundreds of cafes, and hundreds of thousands of jobs to walk to. Perhaps most importantly, the outer suburbs don’t have the constraints on driving and parking that often make walking or public transport a superior alternative in the inner city. Read the rest of this entry »


Who lives in the city centre?

Key demographics, 2006 Census, Melbourne's Core and Inner City

There’s so much misinformation being put about lately regarding apartments and city centre living that I thought it would be timely to put some basic facts on the table. Fortuitously, I recently came across a paper by two academics from the School of Geography and Environmental Science at Monash University, Maryann Wullf and Michele Lobo, published in the journal Urban Policy and Research in 2009. It’s gated, but the tables I’ve assembled summarise most of the salient findings.

The authors examine the demographic profile of residents of Melbourne’s Core and Inner City in 2001 and 2006 and compare it against Melbourne as a whole i.e. the Melbourne Statistical Division (MSD). They characterise the Core as “new build” (60.6% of dwellings are apartments three storeys or higher) and the Inner City as “revitalised”.

The Core is defined as the CBD, Southbank, Docklands and the western portion of Port Phillip municipality i.e. Port Melbourne, South Melbourne and Middle Park. They define the Inner City as the rest of Port Phillip and Melbourne municipalities, plus Yarra and the Prahran part of Stonnington municipality. So what did they find? (but let me say from the outset that the implications and emphasis in what follows is my interpretation of the data, rather then necessarily theirs).

A key statistic is that the share of Melbourne’s total population who live in the Core is extremely small – just 1.7%. So however interesting the demography of the Core might be, it represents just a fraction of the bigger picture and accordingly we need to be very careful, I think, about assuming what goes on there reflects what the other 98.3% of Melburnians think, want or are doing. And the same goes for the Inner City, which has just 5.9% of the MSD population.

When the authors looked at the age profile of the Core they found it is astonishingly young. The proportion comprised of Young Singles and Young Childless Couples is an extraordinary 44.0%. The corresponding figure for Melbourne as a whole (i.e. the MSD) is 15.1%, or about a third the size. And just to emphasise the point of the previous para, note the Core has 26,486 persons in these two categories, whereas the MSD has 542,481.

Households in the Core also tend to be small with only 21.6% having children. In comparison, the MSD might as well be another country – the corresponding figure is 53.3%. Unfortunately the researchers don’t break down the large Young Singles group by household size, but given the predominance of apartments in the Core, it’s a fair bet they tend to live in one and two person households.

I expect it will surprise many to see that Mid-life Empty Nesters make up much the same proportion of the population in the Core (and Inner City) as they do in the MSD. They’re also a small group – they account for just 8.3% of the population of the Core and hence their impact on the demography of the city centre is really quite modest. Read the rest of this entry »


Where is Melbourne’s ‘centre of gravity’ ?

Change in the 'centre of mass' of employment in Melbourne, 1981-2006

We’re familiar enough with the idea of the ‘centre of gravity’ of population in Melbourne. But where is the centre of gravity of employment?

Is it the city centre? No, for one thing the CBD’s only got around 15% of all metropolitan jobs. For another, the combination of Melbourne’s distinctly lop-sided growth south of the Yarra and the fact that 72% of jobs are more than 5 km from the CBD, suggests it’s going to be somewhere south east of the CBD.

So I’ve calculated the location of the centre of gravity (more correctly, the ‘centre of mass’) of jobs from Census data. The accompanying chart shows how that location changed over the period from 1981 to 2006.

The centre of gravity is calculated by dividing Melbourne up into 1,000 traffic zones and weighting the coordinates of the centroid of each zone by the number of jobs it holds. If you imagine a relief model of employment in Melbourne, the centre of gravity is where you’d rest the model on a needle so that it balancess perfectly.

In 1981, the centre of mass of employment was 5.9 km east south east of the CBD, on Kooyong Rd, just north of Toorak Rd. By 2006 it was 7.9 km from the CBD, close to the corner of Malvern and Tooronga Rds.

This movement reflected the much stronger growth in jobs in the suburbs over this period compared to the CBD and inner city. Read the rest of this entry »


Will redevelopment of Fishermans Bend really be ‘revolutionary’?

The Age breathlessly headlines the Government’s proposals for the redevelopment of Fishermans Bend as Premier Ted Baillieu’s “inner city housing revolution”. Planning Minister Matthew Guy says the area will evolve as ”Australia’s first inner-city growth corridor”.

Whoa there! I think it might be time for a relaxing cup of tea and a lie down. Let’s put these claims in perspective.

According to Mr Guy, the area under consideration is 200 Ha. That’s quite a bit smaller than the 41,000 Ha expansion of the Urban Growth Boundary approved last year.

Mr Guy also says the area is going to be developed over a 20-30 year time frame. If its total capacity is the 10,000 to 15,000 dwellings estimated by the Chief Executive of the Property Council, Jennifer Cunich, that’s at most 750 additional dwellings per year on average, and as few as 333 per year.

Just to put that in context, 42,509 dwellings were approved in the metropolitan area in the 12 months ending on 30 September 2010. Ms Cunich is quoted as saying even that’s less than we need – she says there’s a shortfall of 6,000 homes per year across the State.

While the redevelopment of Fishermans Bend is important, the claim that it’s a ‘revolution’ is hyperbole.

Likewise, the Minister’s claim that Fishermans Bend will be a ‘growth area’ – a term usually used to refer to massive outer suburban release areas – is more than a trifle exaggerated. Consider that 17,000 new dwellings were approved in Melbourne’s (outer) Growth Area municipalities in the year ending September Qtr 2010.

The Minister’s claim that the project will focus on “more affordable” housing also seems ambitious. Read the rest of this entry »


What is the inner city?

We all use the term “inner city” but I doubt we’re all talking about the same geographical area.

For some people, the inner city means the area where cafe society thrives – probably a 10 km circle around the CBD in cities like Sydney and Melbourne. Or it might mean the extent of medium density historic terrace housing.

Some Brisbanites think of the inner city as the large area covered by the Brisbane City Council (1,367 km2) while some Melburnians think of it as the area serviced by tram lines.

Planners have addressed this problem by adopting simple measures. For example, in Melbourne the inner city is customarily defined as the area covered by the central municipalities of Melbourne, Yarra and Port Phillip (77 km2). Sometimes the Prahran portion (SLA) of the City of Stonnington is also included.

In my work on Melbourne I define the inner city as the area (79 km2) within a 5 km radius of the City Hall . This approximates closely to the three inner municipalities, but I use it because it’s consistent with what’s done elsewhere. US researchers typically use a 3 mile radius to define the inner city – an area approximating the size of the central Counties of the larger metros.

There are a number of problems with this sort of ‘administrative’ approach. A key one is that there is no underlying rationale for where the boundary is drawn – why not 2 km or 10 km? Another is that it doesn’t really connect with people because it has no obvious reference like, say, the tram network. Read the rest of this entry »