Greenfield housing at Carina Brisbane. Grattan says the large area of the site occupied by the dwelling reduces adaptability in the future

The Grattan Institute released a new report earlier this month, Building tomorrow’s suburbs, on how to make fringe suburbs more adaptable to future change.

The Institute is concerned about the ability of new outer suburban developments to meet the needs of future residents.

Greenfield residential developments may be less adaptable to shifting community needs and preferences than older parts of our cities……If today’s suburbs are to be tomorrow’s suburbs too, then they must be flexible enough to change with the people who live in them.

The focus is specifically on the adaptability of land and buildings. Infrastructure is not considered (I find that astonishing because most infrastructure is expensive to retro-fit).

The report relies heavily on the example of the inner city. It’s diversity and mix of land and building configurations has enabled it, despite its age, to adapt well to modern requirements.

A number of mostly familiar ‘new urbanism’ actions are proposed for new peripheral development. They include more flexible zoning, better connectivity, buildings oriented to the street, and more flexible residential and commercial structures.

The report also recommends a 15 year limit on restrictive covenants. Drawing on the example of Singapore, it also proposes wider use of compulsory land pooling (the authors seem unaware of Australia’s own experience with land pooling).

I don’t think the future adaptability of the outer suburbs is the most pressing or important urban issue the Grattan Institute could’ve examined, but it’s nevertheless a legitimate and interesting one. There are a number of issues that come to mind in addressing this question.

One is how well we can predict the future and plan for it, especially at the level of suburbs. As a society we find it hard enough to predict short-term macro trends much less long-term micro level trends.

For example, state governments generally didn’t do well predicting the upswing over the last five or so years in the demand for public transport. But the really hard bit is the most important bit – planning for changes beyond the foreseeable future, say more than a generation away.

What we really need to be thinking about is how to make our cities adaptable to the unpredictable and unexpected i.e. preparing for unknown changes. That’s especially hard at the sort of detailed level that the Grattan Institute has chosen for its prognostications.

This is different from something like planning for climate change. Truly adaptable suburbs would be flexible enough to cope with a large number of eventualities e.g. with climate change and with no climate change.

Another issue is how much new settlers should pay today to make it easier for future generations (theoretically anyway) to adapt land and buildings to the circumstances of the day. A related issue is how much these first occupants are prepared to pay, given it’s unlikely future users will even be related to them.

As noted, the Institute puts great weight on how well the inner city has adapted to change. There are a few things to think about in relation to that proposition.

One is that the basic pattern of land uses established in the nineteenth century didn’t change much for three, four or five generations – it’s only been over the last 30-40 years that it’s changed substantially. So any upfront investment in adaptability would’ve been slow to get a ‘return’.

Another is the original builders of inner city housing and factories didn’t give much attention to the adaptability of their structures or to the needs of future generations, much less paid any premium. They simply did what made sense in the here and now and in the context of their own foreseeable future needs.

If it turned out that those buildings and streets could be turned relatively easily to new uses, then that was more to do with serendipity than the wisdom of planning. It wasn’t a conscious attempt to anticipate future needs like the Institute is proposing now for greenfield estates.

Perhaps the biggest concern though is that we look at the inner city now with the benefit of hindsight. It’s adaptable because certain things happened.

For example, after quite a few generations, manufacturing left the inner city. That (industry-specific) structural change removed a serious disamenity and made it attractive to gentrifiers. Also, because of changes in fertility, they could happily live in smaller dwellings and have as much space per occupant as in the suburbs.

But the historical path between the nineteenth century and today could have been different in ways that rendered the inner city quite inflexible for current (i.e. counter-factual) circumstances! So when we look forward from now, we can’t know how things will turn out in two, three, four or more generations any more than our nineteenth century forebears could.

I think the sort of level that the Institute is looking at is too detailed and amplifies the scope for uncertainty. The principles that occur to me to maximise adaptability in the longer term are to mostly shy away from the small stuff – including physical design – and focus on the big picture stuff like having flexible and efficient institutions and processes.

For example, the focus should be on removing any impediments and frictions to adaptability, such as hefty stamp duty on property transactions. Prices should reflect real costs rather than implicit subsidies. The cost of externalities should be internalised. Markets should be competitive and our institutions should be open and accountable.

We should be aiming to have a system that can absorb and adapt to change. But we shouldn’t privilege today’s technical and political views, because we can be pretty certain they’ll be completely wrong.

The one exception I’d make to physical design is infrastructure. The odds of getting it wrong are enormous, but we still need to bite the bullet and make high level decisions like reserving land for communication and transport corridors.