Stainless – video by Adam Magyar

I’ve argued before that some criticisms of McMansions are ill-informed and unwarranted, but I’m not very impressed with Chris Berg’s defence of them in the Fairfax press the other day.

Mr Berg, a Research Fellow with the Institute of Public Affairs, makes two points: The first is that “suburban living in general is more environmentally friendly than inner city living.” The second is that large homes aren’t a problem but a sign of our economic success as a nation.

I think it’s disingenuous, at the very least, to claim that “suburban living in general is more environmentally friendly than inner city living.” He cited the well-known Consumption Atlas prepared by the Australian Conservation Foundation (ACF) to support his case:

A study conducted by the Australian Conservation Foundation (no fans of consumer capitalism) concluded that, even taking into account car use, “inner-city households outstrip the rest of Australia in every other category of consumption”.

What he’s glossed over here, though, is the ACF doesn’t conclude “inner city living” is less sustainable than suburban living. Rather, it finds inner city households are less environmentally friendly than their suburban counterparts.

Of course the built environment of the inner city is more sustainable than the outer suburbs! On average, it has smaller dwellings, more mixed uses that support walking, shorter average trip distances, and vastly better access to public transport.

But on average it also has wealthier households. They consume more goods and resources than outer suburban households because they can afford to. That includes flying a lot more for business and leisure.

They are smaller on average too, with many comprising only one or two persons. The consequence is their per capita consumption of space nullifies the advantage of living in smaller dwellings.

These two factors overwhelm the sustainability benefit of living in denser neighbourhoods. However it doesn’t neutralise the benefits of “inner city living” – if these wealthy residents lived in the outer suburbs like their counterparts in most US cities do, their environmental footprint would be even larger.

I also think Mr Berg’s proposition that McMansions are an innocent mark of our success as a rich society – we buy big houses, he says, because we can – skates over the important issues.

That’s true as far as it goes but he should go further – there’s much more to the story. As a matter of public policy, we’re concerned about what cost that choice imposes on the rest of us in terms of emissions, pollution, energy consumption and cost, traffic congestion and infrastructure costs.

McMansions aren’t the only instance of “excessive” space consumption though. As the ACF’s analysis makes clear, we need to think in terms of space per occupant rather than the total size of the dwelling.

I don’t have access to any the figures right now, but I’d expect there are at least as many existing dwellings being extended and renovated across the established parts of our cities each year as there are new McMansions being built on the fringe.

On top of that, every year there are more and more empty nesters and elderly singles rattling around in large family houses and terraces. And then there are an increasing number of young buyers of studio and one bedroom apartments who only a generation ago lived in group houses where they shared facilities and consumed less space per person.

Households who consume a lot of residential space per capita, whatever the built form and location, need to pay the full social cost of that benefit. So do those who fly a lot. Fortunately, at least in the former case, we’ve started to deal with the issue in Australia by way of the price on carbon and mandatory energy ratings.

There are other areas we need to improve too. They include the under-pricing of transport (both private and public) which promotes long commutes from far-flung low density areas, as well as implicit subsidies for home ownership that encourage excessive investment in housing.

Fortunately, I’m not aware of anyone who seriously proposes an upper limit on the size of dwellings. That sounds as feasible as imposing size limits on ovens and fridges, or on the number of flights we’re permitted to make, or the amount of meat we can eat, or the number of children we can have.

If they have to pay their real social cost, households will have an incentive to reduce their use of resources and hence of space. Couple that with eliminating frictions like stamp duty and regulatory constraints on housing supply, and there should be a better match between household size and dwelling size.