Expert: Suburban sprawl a short-term solution

00:04, Apr 20 2013
PREDICTING CITY'S FUTURE: University of Canterbury engineering professor and energy expert Susan Krumdieck.

Is a booming Christchurch swelling in the right places? Or is a property bust in the offing? JOHN McCRONE reports.

'I'll lay down a prediction right now. You give that new house out in the 'exurbs' 10 years and you won't be able to sell it for what you paid to build it," warns University of Canterbury engineering professor and energy expert Susan Krumdieck.

Following the earthquakes, Krumdieck is alarmed about how Christchurch is now endorsing a car-based sprawl.

Check the property pages and you can see where the 12,000 people being pushed out of the red- zoned city suburbs are heading, she says. West Melton, Halswell, Prebbleton, Yaldhurst, Northwood, Lincoln, Rolleston, Pegasus, Rangiora and beyond.

There is a rash of exurban subdivisions being hurried on to the market. Just hop in the car and keep driving until the land becomes cheap enough to build. Worry about the commute to work, schools, shops - everything, really - only after you are settled.

Krumdieck says it is a short-term solution guaranteed to create a long-term headache.


The era of cheap oil is coming to an end, the cost of fuel is only going to rise, she says.

Kiwis have been somewhat buffered because the dollar is so high, but already, in places like the United States and Canada, property values in these kinds of rural fringe and satellite town subdivisions are collapsing.

"We're talking about US$800,000 houses going down to US$150,000 and not selling after a year and a half. Foreclosure rates out of control. Tumbleweed developments."

The McMansion paradises of just five years ago are becoming this century's instant slums. The market has flipped because people are looking at the future and deciding they need to get back into "liveable" city neighbourhoods.

Krumdieck, who is American, spent last year on sabbatical in her hometown of Denver, a classic modern sprawl city, and witnessed it first hand.

"If you look at the advertisements for what is selling, you can count the number of times 'walking distance to the light rail' now turns up. It's the No 1 marketing point. Walking distance to restaurants, walking distance to shops."

It is a generational change as well. Retiring baby boomers and urban-minded Gen Y want to get back into the energy-efficient city. Neither wants to get caught at the end of a highway as fuel prices ratchet up over the next 20 years.

Which makes Christchurch's sudden greenfield expansion a dangerous choice, Krumdieck says - a gamble of the one-time reinvestment of $2 billion in red- zone payouts which could cost the city and homeowners dearly.

But the problem is we cannot seem to imagine any alternatives. What else can poor Christchurch do?

The central city is not an option. It could be another five years before there can be large- scale residential development there. So out into the surrounding countryside the people must go.

As it happens, Krumdieck says, there is an alternative. But be prepared. It is radical.

Over the summer, she gathered together her research team to consider what Christchurch might have done if it had approached the question from an engineer's "first principles" point of view.

It began as a paper exercise, but now having been through it, Krumdieck is wondering if she could actually help make it a reality.

You have heard of a brownfield redevelopment, Krumdieck asks? Well, this is greyfield, the recycling of a run-down neighbourhood. In a nutshell, she wants to build Riccarton Eco- village.

Take four blocks in upper Riccarton - the 133 hectares bounded by the university campus to the north, Peer St and Ilam Rd to the sides, and Blenheim Rd to the south - and bulldoze the existing homes.

Rebuild the entire area as a pedestrianised, post-car suburb of medium density, high efficiency, eco-housing.

Lay on some trams, revamp Church Corner and Bush Inn as a new metro hub, move in 20,000 people where 4000 people used to live, and by relocating red-zoners within the existing city limits, there is your sprawl issue solved.

Well, let's not make it sound quite so easy, Krumdieck says.

But here is how the plan falls quite systematically out of taking a clean sheet of paper and thinking about how to rebuild Christchurch in a rational future-proof way - one that might actually preserve the value of that $2b housing reinvestment for the next 100 years or more.

An engineer starts a project by outlining the constraints. Krumdieck says first it can be taken as read that fuel prices are going to become ever more of an issue for society.

Fracking in the United States might have staved off peak oil, the date when world fossil fuel production reaches its maximum and the inevitable decline in supply begins, Krumdieck says - perhaps no-one believed America would be quite so environmentally reckless about digging up its own backyard - however, that move can buy only a few years.

"Yes, we're pretty gleeful about fracking, but the price of gas is still approaching US$4 a gallon in the US. Nothing's really been changed. Our analysis is that 2016 is when it is all going to fall over big time."

So from the point of view of sustainable suburbs and the need to cut car journeys to a minimum, the next oil crunch could still be arriving rather soon.

This led Krumdieck's team to draw up a map of Christchurch's existing fuel vulnerability. If you live in a suburb, could you walk or cycle to most things if you had to? Krumdieck says the good news is that most of Christchurch is in fair shape.

The city has grown in a reasonably contained fashion. The sea and the Port Hills have formed natural boundaries on development. Christchurch has also enforced green belt policies in the past. In particular, the protection of the airport has created a barrier to expansion all along the northwest fringe.

So just a few suburbs, like Parklands, Southshore and Diamond Harbour, are "energy red-zoned" because they are too distant from natural activity centres like schools, shops and businesses to adapt easily to future oil shocks. Krumdieck says it is only with the new exurban sprawl that Christchurch would be building itself a real problem.

This energy map was then narrowed by looking for TC1 land, free from any risk of liquefaction.

"We've got 12,000 red-zone people to be housed ASAP. So we can't be taking the time to get approval for new kinds of foundations. We need to build what we know we can build on solid ground and get it done."

That put a ring on the map stretching from Burnside to Hornby. Finally, came the clever bit, the hunt for a neighbourhood begging for wholesale revitalisation - the part that makes the whole notion of greyfield development economically viable, Krumdieck says.

Brownfield development has become a familiar concept, she says. All around the world, in every city you visit, the old dockyards, railyards, stockyards and warehouses have been turned into something nice.

Industry moved out, leaving behind derelict eyesores. But now these sites have been converted into downtown shops, apartments, galleries and museums.

Krumdieck says most big cities today are faced with a new emerging kind of slum - the early car-based suburbs that sprang up between the 1930s and 1960s.

You know the kind of thing in Christchurch, Krumdieck says. Rows of clapped-out weatherboards or cheap brick and tile homes. Big gardens, yet little value in the structures.

"The code that those houses were built to is just not acceptable now. And the form of those houses does not fit what is our demographic."

It would cost too much to bring the houses up to date with double glazing and good insulation. It is hardly even worth keeping them maintained. So most become rentals. Or at best, they are bowled and infilled, their plots converted into a pair of town houses or three granny flats.

We don't like to call them slums, but they are, Krumdieck says. Inadequate housing that we can't seem to do much about. So imagine instead being able to bowl a whole such suburb and replace it with a master-planned eco-estate built from scratch.

Consider the savings. Krumdieck says to build an exurb, someone - mostly the community - has to pay for new roads, new sewers, new schools, new parks, new medical centres. But with a greyfield development, all that infrastructure is in place.

And then the actual construction would be far more efficient. With an exurb, the developer provides bare sections and the houses are individually built. But with a greyfield development, you could start at one end and work your way across a block. There would be one site entrance, one crew. Costs could be slashed to the bone.

The advantages keep stacking up. Krumdieck says much of the expense of a new home lies in the land, but with townhouse or condominium-style development, the land could be owned by a corporate body.

"You don't actually have to own the bit of dirt under your home, you know."

It might demand a change in home ownership culture in Christchurch, but it would deliver the kind of affordable housing that everyone says the city needs.

"You can drop the price way down. You can have a $100 a week two-bedroom house. Why not?"

The running costs would fall too, says Krumdieck. Instead of paying $500 a month through winter to heat a draughty weatherboard house, an insulated three-bedroom apartment with a passive solar design should see an electricity bill of $40.

"It's just engineering. We know how to do this."

It seems so logical, she says. Instead of building potential future slums - unsellable McMansions on the outskirts - use that same money now to buy out an existing greyfield slum. All it takes is to imagine it is possible.

The Press