‘Any city would consider itself fortunate to have a Dan Gilbert,” Detroit’s planning director, Maurice Cox, tells me. “He walks the walk, he talks the talk. He not only bought a significant group of buildings in the downtown core, he also brought along with him thousands of his employees. Gilbert’s repurposing of buildings downtown, in turn, fuels the desire for a lot more urban downtown amenities…Gilbert’s doing his part and he’s doing it brilliantly, and I’m really glad there’s a Dan Gilbert in downtown Detroit so that I can turn my attention to Detroit neighbourhoods, where Detroiters live and where there is no Dan Gilbert.”

Whatever the truth about Quicken’s role in the housing crash, there’s no question many of Detroit’s poorest neighbourhoods were finished off by the subprime crisis. They’re also where you find the worst of the city’s blight. Abandoned houses, arson, gun crime, drugs, no public transport, no functional businesses except liquor stores and fast-food joints — this is still the daily reality for much of Detroit’s population.

The state of Detroit’s outer neighbourhoods kicks the recovery narrative into touch. This is where America’s post-industrial rubber really hits the road. And that makes Cox — a charismatic African- American New Yorker in his late fifties — one of the most important urban planners in the world right now.

“Urban revitalisation takes on very specific patterns,” he tells me, pointing occasionally at a massive, heavily marked map on the wall behind him. “It starts from the centre — the heart of the city, its downtown and immediate adjacent neighbourhoods, its riverfront. In Detroit, that’s an area of 7.2 square miles. From here, revitalisation progresses slowly outward, to what I argue is the soul of the city, which is its neighbourhoods. But when you have 138 square miles to regenerate, the soul of that city is very far away from its heart, and it takes longer to get to it.”

Beyond the Gilbert-led downtown and midtown resurgence, there’s no meaningful property market in Detroit. For Aucklanders, it’s almost impossible to picture how bad things got. You could buy whole neighbourhoods for less than the cost of an ex-state house. A perfect Mies van der Rohe townhouse set you back less than $100,000. In 2013, on my first trip to the city, I met a guy who bought an ex-police station off the city for five bucks, because they didn’t want to leave it to arsonists.

“We talk about the ‘missing middle,’” Cox continues, “which is the housing between a single-family detached house with a yard, and a high-rise apartment building. Almost everything in between — condos, courtyard houses, row houses and townhouses — is basically missing in Detroit. While the city was managing population decline, it wasn’t building these new kinds of urban houses, but we’re finally starting to see that change. The only place that type of investment pencils out, however, is in the downtown, and the immediately adjacent neighbourhoods. Even there it still requires public subsidy.”

Cox’s strategy in the outer neighbourhoods is completely different. It’s also radical, brilliant and based on a single driving principle: fairness. “Having been off the radar for a few decades, neighbourhoods that failed to attract new residents are now at an advantage. As revitalisation begins to happen in these neighbourhoods, we can ensure equity is a critical component.”

Cox’s neighbourhood experiment, currently under way in pockets around Detroit, refuses any new construction of single-family homes. Instead, the city works with developers to rehabilitate those houses still standing. The economics of this strategy, he points out, are pretty straightforward. If new construction of a single-family home costs on average, $120,000, but that home is surrounded by others that are only worth $60,000, a developer loses $60,000 right out of the gate. If instead they spend an average of $60,000 to renovate an existing home, and the city makes a critical mass of properties available, the numbers start to work out.

In Cox’s plan, the developer has two specific obligations. First, they have to rehabilitate properties for affordable rental and eventually home ownership, which Cox sees as essential to equity and inclusive growth. “We want to prevent this development from leading automatically to gentrifying the neighbourhoods,” he says. “The idea that the city would put in millions of dollars to protect affordability wins a lot of people over. Typically, the housing model focuses on single-family ownership, and that really means renters are unwelcome. We believe we can regenerate a neighbourhood and assure rental possibilities remain.”

And second, developers are required to take on vacant lots adjacent to each house they rehabilitate. Single vacant lots must be made visually appealing, and multiple lots must aggregate into a communal area like a park or be turned into neighbourhood-scaled businesses like cut flowers or food production.

“People in Detroit have been squatting on land for years,” Cox says, “unable to convince the city to sell. Now we’re talking about these lots not as the land use of last resort, but as generative. Furthermore, the people running these productive land businesses are residents — entrepreneurs who have continuously struggled to get half an acre, a third of an acre. Now the city is creating a framework for residents to not only own these lots but to manage them successfully.”

The productive land strategy is intended to create economic activity and increase the desirability of the neighbourhoods. But it also saves the city money in the long term. As Cox points out, across America the green-space strategy has long been one of spreading grass seed and creating a mowing regime that costs millions in maintenance every year.

But perhaps the most extraordinary part of his plan is something that seems anathema to the very idea of the Motor City: making the bicycle a primary mode of transport. Detroit is flat, with wide arterial roads. That leaves plenty of space for cycle lanes. Cox argues that bikes are a crucial piece in the affordability puzzle. In Detroit, a third of residents can’t afford a car, and the city’s insurance rates are amongst the highest in the country. Safe, functional cycleways help alleviate that cost.

The overall idea is to create what Cox and his team call “20-minute neighbourhoods”, where residents can access all the urban amenities they’d expect — fresh food, schools, libraries, public transport links and so on — within a 20-minute walk or bike ride from home.

These 20-minute neighbourhoods will then be linked to the city’s major commercial corridors via an enormous bike network. To help build it, Cox has brought in the team that developed Copenhagen’s incredible cycle system.

As our conversation goes on, I want to bundle Cox into my luggage and smuggle him to Auckland. He tells me about “pink zoning”, a concept where City Hall works with residents and developers to reduce bureaucratic red tape so that more land is available for mixed-use and sustainable projects. He talks about historic preservation, developing the waterfront, working with start-ups, greening the city; about creating a healthy, fair, dynamic, multicultural urban environment out of one of America’s biggest urban tragedies.

And it’s not just talk — it’s happening. The difference between Detroit’s ability to do this and Auckland’s urban crisis is stark. In Detroit, because there’s no functional property market, no one has anything to lose. It’s hard to be a nimby, because almost everyone’s backyard is fucked. Auckland, as we know, is a different story. The contrast shows just how oppressive our insane house prices are on future-oriented thinking.

But what about jobs, right? It’s one thing to pretty the city up, but people are going to come back to Detroit only if there’s work for them.

Quicken Loans is one major company that calls Detroit home. Another is the enormous pizza chain Little Caesars, which has unveiled plans for a new HQ on Woodward Ave, the façade of which will have 4.3-metre glass windows shaped (seriously) like pizza slices. Its owners, the Ilitch family, also own the ice-hockey franchise the Detroit Red Wings, and are building a new stadium for them called Little Caesars Arena. No prizes for originality.

But pizza and mortgages aren’t exactly 21st-century industries. Nor is auto, or at least the auto Detroit was built on. The challenge, then, is to figure out what Detroit’s next big opportunities will be.

A major answer is coming from the creative sector. Toby Barlow, 50, is a novelist who moved to Detroit in 2006. Four years ago, he co-founded the “Write a House” programme, a scheme which buys vacant houses, fixes them up, and then places a writer in residence. If the writer stays for two years, they get the deed to the house.

“One of the main issues the city has is a narrative problem,” Barlow explains, when I ask him why he set the programme up. “There’s only so much truth a writer in Auckland can garner on a Skype call, or a writer from San Francisco flying in for a weekend… There are some truths to be told about what’s going on here, and not just one truth through one set of eyes. So the idea that we could invest in and celebrate the narrative of this place, and fill the city with writers who would be interested in it, captivated my imagination.”

As his day job, Barlow works in advertising, as the creative director for Ford’s campaigns. He points out that even though auto manufacturing has changed, it’s still very present in the city’s life, and there’s an enormous amount of auto-connected work. The federal bailout, particularly of GM and Ford, seems to have achieved what it was for, dramatically reducing the long-term impact of the global financial crisis on Michigan’s car industry.

“It’s a really interesting time to be in automotive,” Barlow says. “The ­multidimensional technologies and voice recognition work, hybrid work, energy work, fuel-cell work. It’s a hell of a lot more dynamic than it was in 1978, when it was, ‘How big an engine can you put in there? And maybe a seatbelt.’”

Unesco recently designated Detroit a City of Design, and it’s easy to see why. The growth of the American auto industry was predicated on good design as much as technology, and the local art and design schools have been integral to this for decades. Cranbrook Academy of Art, for example, is often spoken about as the cradle of American modernism. Charles and Ray Eames, Eero Saarinen, Steelcase and Herman Miller all started in or near Detroit. And Detroit’s College for Creative Studies still produces many of the world’s best car designers.

“This is a city that is obsessed with making things,” Barlow says. “It’s the furniture capital of the world. Michigan has great stuff in that way. With the automobile, the musical culture, and that heritage of craftsmanship, there’s a lot here.”

One of the growth areas Barlow points to is what he describes as “honest luxury” brands, like Shinola Watches, Detroit Denim, Detroit Bikes, and a high-end shirt company called Lazlo — all of which pay living wages, don’t outsource jobs, and use, where they can, sustainable materials.

It’s an awful lot cleaner than the industries that shaped Detroit and other cities like it. The cars are getting cleaner, too, with companies like Ford leading the way on mass-produced hybrid and electric vehicles.

Detroit and its new employment opportunities are providing a model for how you turn a Rust Belt city green. Michigan is one of America’s largest agricultural producers, with the second-biggest diversity of fresh produce in America behind California. Eastern Market is where you find it: an enormous, well-functioning fresh-food market, which both Cox and Clark describe as one of the city’s most democratic spaces and is regarded by everyone I’ve ever met there as one of Detroit’s greatest assets.

The produce is always local, cheap and seasonal. Detroit solved the air-miles question years ago, out of necessity, because none of the major supermarket chains wanted to open up there. Eastern Market is about to go through a major expansion, including building new, affordable housing for its workers.

But the most intriguing part of Detroit’s green future is blue. America’s Great Lakes hold around 20 per cent of the world’s freshwater reserves. Michigan is squeezed between several of them. The question is how to both protect and monetise the water at the same time. No one seems to have the answer yet, except there’s wide agreement it won’t be a case of building pipelines out to dryer states.

Here’s the record-scratch moment, though. You don’t go through a century of auto manufacturing without producing massive amounts of pollution along the way. There’s plenty of Detroit that still needs to be cleaned up. Then there’s the Flint water crisis, which made international headlines earlier this year. Flint, one of Detroit’s desperately poor satellite cities, was rocked by the discovery that it had a lead-poisoned water supply — all because a few city administrators were trying to save a tiny amount of money each year.

There’s a horrible irony here, as Barlow points out, which is emblematic of the kinds of contradictions that still plague Detroit. “The idea that you’re sitting literally next to the largest freshwater resource in the world, and you can’t get water to the people in a healthy way — what does that say?”

I suppose one defence is that at least Detroit’s pollution of its waterways is historical, and that they’re trying to find ways to fix it. As the Havelock North contamination debacle and Massey University ecologist Mike Joy’s outstanding freshwater research have shown, I’m not sure we can say the same thing.