Are huge homes irresponsible?

Huge houses on the urban fringe are an irresponsible drain on the environment, according to this opinion piece by Dr Robert Crawford from Melbourne University. There are two charges here – one is that the average 238m2 greenfield house is too big and the other is that the occupants are too reliant on cars for transport. I discussed the transport issues related to greenfield houses recently, so this time I want to look at the allegation of excessive dwelling size.

There are all sorts of problems with the “too big” criticism, not least the obvious question: what is the “right” size for a dwelling? Even if that question could be answered satisfactorily, there’s another – what should be done about it? Should there be regulations limiting the size of houses? Or perhaps a “McMansions” tax? I think there’s actually a sensible way to approach this issue which I’ll come to in due course. But I want to start with some pertinent observations.

First, greenfield houses mostly aren’t as big as epithets like “McMansion” imply. When Melburnians think “McMansion” they usually have in mind a two storey house like Metricon’s 530 m2 ‘Monarch’, which is more than double the size of the average greenfield house. In the US however, the term McMansion is reserved for much, much bigger houses on very large lots like Tony and Carmela’s spread in New Jersey (see first picture). The average house on Melbourne’s fringe, however, is a much more modest 238 m2 according to Dr Crawford’s own evidence. That’s big compared to an inner city apartment but it’s much smaller than the ‘Monarch’ and much smaller than any reasonable definition of a McMansion. Further, more than two thirds of houses in Melbourne’s greenfield areas are single story. Nearly half (47%) are smaller than 240 m2. Almost three quarters (74%) are smaller than 280 m2.

Second, fringe houses aren’t much bigger, if at all, than typical houses in some older suburban areas. I live with my family 8 km from the city on the border of Ivanhoe and Alphington where most dwellings were built before WW2. Having two children who went to Alphington Primary School means I’ve seen inside many, many homes in the Alphington, Fairfield, Ivanhoe area. I can’t recall ever being in a house in these neighbourhoods that hasn’t been extended at least once in its lifetime. And while they probably were once, these aren’t small houses anymore. For example, the external dimensions of our place, including the garage (but excluding decks), is 240 m2 and it’s by no means large relative to other detached houses in the area – in fact I’d say it’s about average or perhaps even a bit smaller. Yet I don’t hear many complaints that inner suburban homes are “too big”. Read the rest of this entry »


Are apartments the answer to ‘McMansions’?

Annual per capita greenhouse gas emissions for the alternative housing scenarios

Demonising sprawl seems to be the mission of many planners, academics and journalists, but oftentimes zealotry leads to mistakes, as with this claim that infrastructure costs on the fringe are double those in established suburbs. I’m reminded again how easy it is to get the wrong end of the stick on this issue by a study released last week by the Architecture Faculty at Melbourne University.

The University’s media release tells us the study found “houses on Melbourne’s suburban fringe are responsible for drastically higher levels of greenhouse gas emissions compared to higher density housing or apartments in the inner city”. The Age ran with the media release, reporting that bigger dwellings and more car-based travel are the key reasons fringe houses consume more energy and emit more greenhouse gas than apartments.

I can’t refer you to a full copy of the study because the University didn’t make it available to the media or the public. That didn’t seem to worry The Age, but I think it’s an extraordinary decision – does the University exist to issue media releases or to undertake serious research? I contacted one of the authors who told me the study is a journal article and he couldn’t give it to me for copyright reasons. He gave me this link to the abstract. I’ve read the full article but if you don’t have on-line access you’ll have to spring for €35 if you want to read it.

A key part of the study is a comparison of the (embodied, operating and transport) energy consumption and greenhouse gas emissions of households in three building types – a 100 m2 two bedroom high-rise apartment in Docklands 2 km from the city centre; a 64 m2 two bedroom suburban apartment 4 km from the centre in Windsor; and a 238 m2 detached house in an outer suburban greenfield development 37 km from the centre (the latter is shown in the accompanying chart in two versions – a 2008 five star and a “future” seven star energy rated version).

I don’t know what the point of this sort of comparison is. Putting transport aside (you’ll see why later), there’s little policy value in comparing a $1 million plus Docklands apartment with a $500,000 plus suburban apartment in Windsor, much less comparing both with a $350,000 house and land package on the urban fringe (and I’d say Windsor is inner city!). Nor does a seven square two bedroom apartment seem like a practical substitute for the sort of household that buys a 26 square four bedroom house.

A better approach would’ve been to compare the greenfield house against a townhouse of similar value located in the established suburbs, say 20 km or more from the centre (or perhaps against a greenfield townhouse set within a walkable neighbourhood). Alternatively, the authors could have followed the ACF’s lead and compared the resource use of all suburban residents with those of inner city residents – but the catch here is the ACF found that, even though on average they live in smaller dwellings, inner city residents have a higher ecological footprint (see here and here)!

The study should be on firmer ground when it compares transport energy and emissions across the three locations, but it isn’t. The trouble is the study gets it completely wrong on this key variable and, frankly, the travel findings just don’t stand up. There are two key weaknesses. Read the rest of this entry »


– Where do university workers live?

Region of residence within Melbourne of university workers (%)

I’ve said before that there isn’t one ‘Melbourne’ – there are multiple ‘Melbournes’. The home range of Melburnians is pretty restricted – the great bulk of their travel is made within a region defined by their home municipality and contiguous municipalities. Many suburbanites rarely visit the city centre, much less the other side of town.

This pattern of sub-regionalisation is illustrated by Melbourne’s three major universities. I posted on March 16th about the mode shares of work trips to these universities. To summarise, at the time of the 2006 Census, 41% of Melbourne University staff drove to work while over 80% of staff at Monash and La Trobe Universities commuted by car.

The accompanying charts look at something else – where university workers lived in 2006. They show a number of interesting things.

The first chart indicates that staff of these three universities don’t tend to live west of the Maribyrnong. The west has 17% of Melbourne’s population but houses only 8% of Melbourne University’s staff. The ring road provides good accessibility from La Trobe to the west but even so, only 3% of the university’s staff live there.

Second, Monash and La Trobe serve distinct regional markets, in the north and south (of the Yarra) respectively. Melbourne University has a more metropolitan ambit but it still has a sub-regional focus – its staff strongly favour the inner city and the inner northern suburbs.

Third, university staff like to live close to their employer. This is particularly evident with La Trobe, where 56% of staff reside within the four municipalities closest to the university i.e. Darebin, Banyule, Nillumbik and Whittlesea (see second chart). Read the rest of this entry »


Why is transit’s share low at Latrobe Uni?

Mode shares (%), 2006 Census

Workers who commute to Melbourne University at Parkville are much more inclined to use public transport than their colleagues who work at suburban Monash or Latrobe universities. The chart shows that at the 2006 Census, 41% of Melbourne University workers reported they drove to work compared to 83% at Monash and 84% at Latrobe universities. Many more staff at Melbourne also walked and cycled – 24% compared to 6-7% at the other two institutions.

Melbourne University’s lower car use is explained by a few key factors. The main one is that it is located on the edge of the CBD where car use is limited by high levels of traffic congestion and expensive all-day parking charges. For many staff, driving would take too long, generate too much angst and be too expensive. If the value of driving is marginal, the decision to choose an alternative will be tipped by the high quality of public transport service available to Parkville workers. Although it’s not served directly by rail (none of these universities are), Melbourne University has easy access by multiple tram lines to the CBD and thence to the many radial train and tram lines linking to the larger metropolitan area. For many Melbourne University workers public transport would be a no-brainer.

Melbourne University’s high level of walking can largely be attributed to the relatively high residential densities in the nearby CBD and inner city environs. If transport is expensive in outlays and time, it makes sense for workers to live close to the university. In this case, living close to the university also means living close to the many activities and opportunities offered by the inner city.

The suburban setting of Monash and Latrobe provides a very different environment. Although these universities are not without their challenges, they generally experience less traffic congestion and enjoy cheaper parking than Melbourne University. Low suburban residential densities and large open space and industrial uses mean fewer staff can live within walking distance. The level of public transport service is actually pretty reasonable by prevailing standards (for example, see here) but obviously not as good as Melbourne University, which benefits greatly from its proximity to the CBD. Read the rest of this entry »


Do GPs who are co-located with pathology services order more tests?

Click to estimate the cost of getting sick (US)

I’ve cautioned before about the dangers of physical determinism i.e. glibly assuming that the physical environment (or geography) is the driving force underlying human behaviour. Sometimes it is, sometimes it exacerbates another problem, but more often it’s the symptom rather than the cause.

So it was with interest that I noted a new study reported in The Age today that investigated if Melbourne and Sydney GPs who are co-located with pathology collection centres tend to order more tests than GPs who aren’t. I’ve had a look at the study, undertaken by the Melbourne University School of Population Health, in the latest issue of the Medical Journal of Australia.

The study defines co-location as where a GP and a pathology centre are located in the same premises. This group was compared with GPs located at least 50 metres from the nearest pathology centre.

The hypothesis that co-location might lead to a higher propensity to order pathology services seems plausible given, as the authors say, that many studies have shown how doctors’ contact with the pharmaceutical industry can influence their clinical decision-making: Read the rest of this entry »