Tim Ross did architects a disservice in his recent ABC-TV program, Streets of Your Town, by ignoring their much larger role today in designing housing than in the sixties and seventies. He did fringe suburbanites a disservice too, by unfairly comparing a small and unrepresentative sample of ’60s and ’70s detached houses (the relative few done by modernist architects) with an unrepresentative sample of mass-produced detached houses today (“McMansions”).

While some is, most fringe housing isn’t anywhere near as big as the behemoths in the Perth beachside suburb of Iluka that Mr Ross sought to represent as typical of contemporary suburban housing (see Does ABC-TV’s Streets of Your Town get it wrong?). His opening drone-high shot emphasised the scale of these “McMansions” in Romano Crescent much more effectively than the street-level view of the same houses (see exhibit).

But of course he’s right that today’s new detached houses on the urban fringe are, on average, much larger than their counterparts in the ’60s and ’70s. That’s true at all price points. Why is it so? We know it’s not because households are getting bigger; in fact, on average they’re getting smaller.

Here are some possible reasons why today’s average outer suburban households build much larger detached houses than their parents or grandparents:

• House buyers today are more ostentatious.
• Adult children stay at home longer. Average household size is falling but the lifespan of families is increasing.
• More people work from home.
• We entertain more at home.
• Air-con and central heating is cheaper to install up-front and can be zoned.
• Extra dwelling space is cheap relative to the cost of the land due to the greater efficiency of the house building industry.
• Housing today is regarded by buyers as both an investment decision and a shelter decision e.g. “extra space is a good investment”.
• Households are wealthier; they can afford more “stuff”, including more space.

In my view the last three are the key ones – we buy bigger houses now compared to 50 years ago because we’re better able to afford them; because they’re significantly cheaper to build; and because they’re an even better financial proposition than they were in the ’60s and ’70s. There’s nothing remarkable about people buying more of something desirable – like more dwelling space – as the effective price drops. It’s similar reasoning to why they’re simultaneously buying smaller lots i.e. because the effective price of land has increased by an order of magnitude compared to the good old days.

We should be careful though about tossing around the term “McMansion”. In his 2012 book, Coming apart: the state of white America 1960-2010, Charles Murray uses the term to describe suburban houses in the US in the 15,000 – 20,000 sq ft range i.e. 1,400 – 1,900 sq m. That’s three to four times larger than the biggest home – the 450 sq m faux Frank Lloyd Wright Chicago – currently offered to Australian buyers by Metricon (see Are houses so big they’re unseemly?).

Dr Murray adds another explanation for US “McMansions”; those in the top 10% are much wealthier today relative to the average household than their counterparts were in the 1960s and are only too willing to flaunt it. He recommends viewing an episode of Mad Men to see the sort of house – remarkably modest by today’s standards – that “the creative director of a major New York advertising agency might well have lived in”. There’s a resonance here with Australia’s uber-wealthy, although I suspect our version of ostentation is more likely to be located in Toorak, Bellevue Hill or Byron Bay than in an outer suburb.

These various reasons might help explain why houses have gotten bigger over the decades, but is the change a good thing?

Mr Ross isn’t alone in dissing the desire of outer suburban households for more built space; that’s standard practice. But very few Australians don’t opt for more space when they can get it. Provided the location is right, they will pay a big premium for a detached house over a multi-unit dwelling. Larger apartments, terraces and town houses command a higher price than small ones no matter where they’re located. It’s virtually impossible to find an inner-city terrace that hasn’t been extended; and it’s getting harder to find a detached houses in the inner suburbs that’s never been extended in some way. Account for the difference in average household size between inner and outer households and it’s not clear the difference in per-capita space consumption is as large as is usually assumed.

The common criticism of fringe houses – and not just McMansions – is that they’re environmentally irresponsible. But that charge isn’t as straightforward as it might at first appear. Fringe houses have dramatically improved their energy efficiency in recent years. According to researchers at Melbourne University, the per capita operating energy required by the average new greenfield dwelling in 2008 was about a third lower than it was in 2000. In fact, it was lower than it was in 1960, nearly 50 years earlier, notwithstanding the size of the average new greenfield dwelling, they say, more than doubled over this period. The embodied energy of the greenfield house increased slightly between 2000 and 2008, but this was in large part due to incorporating measures to reduce operating energy use (see Are huge homes irresponsible?).

Notwithstanding their large houses, outer suburban residents on average have a smaller negative impact on the environment per person than inner city residents (see Are inner-city residents bad for the environment?). According to a study by the Australian Conservation Foundation, the environmental benefit of smaller dwellings and higher densities in the inner city is overwhelmed by two factors: one is that inner city residents are wealthier on average and so buy more “stuff” and travel more by air; the other is their smaller average household size means their environmental impact is spread over fewer persons. The ACF notes:

In larger households, people tend to share common living areas, which will lower the per-person heating and electricity bills. In addition, larger households can share items such as furniture and appliances, whereas a person living alone must own a full suite of such items. It is also reasonable to think that larger households are more likely to cook together, resulting in more efficient purchasing patterns and lower levels of food waste.

So larger outer suburban houses are mostly a result of lower building costs, higher incomes and favourable tax incentives. The impulse toward ostentation is hardly new; c.f. the palatial 1958-65 Gruzman house highlighted in episode two of Streets of Your Town. For many today it manifests in their choice of location and focus on “design” as surely as for others it’s size that matters. But let’s not lose sight of the fact that detached houses are no longer the main game e.g. they only accounted for one-third of new dwelling construction in the Greater Sydney Region over the last five years.

This article was first published by Crikey. Alan Davies is Editor of The Urbanist blog.