Depending on where you draw the line, Paris has either roughly the same population as London — ten million within the M25 or the “Grand Paris Region,” give or take — or less than a quarter, with only two million people living within the Périphérique, the 1960s motorway that encircles the historic city.

Whereas, thanks to the Luftwaffe and the London County Council, most of London’s working class lives in London proper, with everywhere except perhaps Belgravia and Mayfair having large council estates, in “Paris proper” only the north and east have anything like the same social mix. Even the transport system feels segregated — the historic Métro for “Paris,” the futuristic but shabby and foul-smelling RER for the “Paris region.” So every time I’ve visited, I’ve taken an RER journey out to the banlieues, the suburbs, to spend some time in areas where you can see something a bit more exciting than endless six-story limestone blocks of flats built under Napoleon III.

This is Paris’s historic “Red Belt,” a girdle of concrete where most of the Parisian working class lives, where the Parti Communiste Français built its strongest base, and where, unlike much of formerly industrial France, the Left, whether the socialists, the communists, or Mélenchon’s various vehicles, still dominates the political scene. As with London, this place has voted consistently for the Left for a century, yet it is too multicultural and diverse to be considered anyone’s “heartland.” It’s a fascinating and thrilling place, though it can be bleak — and if the French capital has a future, it is being made there.

Much of the virtue of Iain Chambers’s great Radio 3 documentary Concrete Paris, broadcast at the end of February, is that after a year in which leaving London — let alone Britain — was barely possible for me, I felt like I was taking a virtual RER, reminding me of my trips out to Marne-la-Vallée to see Ricardo Bofill’s extraordinary and bizarre Espaces d’Abraxas, or walking through the skyways of La Défense to the gorgeous and strange pop art housing estate of the Tours Aillaud in Nanterre. Early on in the program, you can hear the SNCF jingle echo through a train, sounding vaguely like something by Ryuichi Sakamoto, and you know that for the next thirty minutes you’re not in lockdown in Britain anymore.

Concrete Paris combines a sound collage made from the fabric of the buildings it describes — recordings made from the concrete and steel, the wood and leaves — alongside interviews with residents, architects, and planners out in the banlieues. It’s the kind of documentary you don’t come across much nowadays. Nobody tells you they’re “going on a journey,” nobody is patronized, and you’re left almost alone to interpret what is happening; yet this lack of hand-holding makes it all the more atmospheric and suggestive as an exploration of a habitually ignored landscape

According to the narrator, Robin Wilson, who composed a brutalist Paris map for publishers Blue Crow, the aim is to “break the myth of Paris,” finding in the process “very different people” with “very different experiences of what Paris is” from those that are usually discussed and showcased. Those myths exist on the Left just as much as the Right.

While conservatives understand the area through Islamophobia and social paranoia — a fear of the riot-prone hordes beyond the Périphérique — much of the Left has mirrored this in writing the entire suburban expanse off as a failed statist experiment, a Gaullist or Stalinist dead zone, a set of brutalist ghettos where the poor have been condemned to live against their will. Concrete Paris ignores both of these over-familiar perspectives, and approaches the area not as “a problem” but as a place, which is highly refreshing.

Its soundscape intersperses clangs, scrapes, birdsong, the sounds of infrastructure, and human activity; the interviews are all translated through an interpreter, which removes some nuance for non-French speakers, though the interpreters have various accents and tones to try and capture some of it. We begin with the suburb of Ivry-sur-Seine, and specifically its famous “Étoiles,” a pyramidal, mountain-like public housing estate made up of a succession of concrete terraces, designed by Jean Renaudie and Renée Gailhoustet in 1969.

One resident describes these “stars” as being “like a mountain village or a small green hill,” as the sound collage implies electronic crickets in the undergrowth. Another resident tells us that “pedestrians are the kings of the town center here — they can go in all different directions, at different heights, so it allows them to take ownership of the whole town center.” This has meant a great deal lately — “as we’ve seen in lockdown, it’s a lot more pleasant to be locked down in a flat with a large terrace than without one.”

But it’s not all utopia here — another resident notes how the low insulation standards of the time mean that you can hear your neighbors when they sneeze. She also notes that you can constantly hear birds in the courtyards, in “a microclimate at the back of the building […] from time to time the birds give a concert in the town center,” which we can hear in turn — so that “with all this greenery it’s like the countryside, a mixture of the town and a little bit of elsewhere.”

We then shift to Créteil, and its so-called cabbages, a series of towers with a striking, organic design, and listen to its 90-year-old architect, Gérard Grandval. He makes clear that his design for the suburb was a reaction precisely to what he thought had gone wrong in the banlieues beforehand: “neighborhoods where there was no activities other than housing — this was obviously wrong, and was criticized.”

In response, the designers of Créteil “aimed to create neighborhoods and an urban life, not just ticking the box of housing people.” While the banlieue was conventionally condemned by the 1968 generation and its heirs, Grandval remembers his design as an explicit reaction to the events of that year. The mayor of Créteil asked the architects to “‘show us that something different is possible,’ and I took him at his word.”

Some of this has clearly rubbed off. We hear one resident point out that here “we’re not in boxes, but in flats that are like slices of Camembert. […] If you go from one room to another, you feel like you’re outdoors. It’s like a kind of village here, and it’s all linked to the architecture,” which is evoked by stark, epic whistles and drones. Grandval is happy with the gradual additions being made to the suburb, and disdains architects who “think they’ve built the Parthenon.” “I want people to change my buildings. At the end of the day, they’re people’s homes.”

The final destination is the suburb of Bobigny, and its remarkable Bourse de Travail (i.e., Job Center) by the great Brazilian modernist Oscar Niemeyer, a cousin of his stunning Communist Party headquarters in northeastern Paris. But here for the first time we hear a dissenting voice — and, perhaps surprisingly, it’s from a professional, the urban planner working in Bobigny’s town hall.

He speaks well of the town center — “we are not a ghetto” — but is otherwise scornful, as “we have one nearby, at the Cité Paul Eluard,” where “you really feel” that the people there have been closed off. Of course, there’s a great deal of truth in this — and the further out you go in the banlieues, the more often you’ll find careless or regimented townscapes without public facilities or RER stations, every bit as often as you’ll find underrated gems like the “Stars” and the “Cabbages.”

The Bobigny planner goes further, though, and claims that the effort to separate people from traffic — specifically praised by the Ivry-sur-Seine residents — means “we ended up creating enclaves, ghettos, where people went round in circles.” Although it is here that you’ll find the most diverse, multicultural places in France, the planner laments that with the concentration of “people on benefits,” these areas have “no social mix,” and “the most dynamic people leave.”

Of course, he’s not completely wrong — the Parisian model of putting most of the social housing outside the ring road is clearly a bad one, and the fact that it was largely done to preserve the historic image of beautiful, untouched Paris is a good reminder of why sometimes conservation and conservatism aren’t quite so far apart as we’d like to believe. But it is immensely striking to go from these stories of successful, unusual working-class housing to this sour statement of contemporary neoliberal planning ideology.

The architects of the banlieues may have thought you could solve poverty through housing — and while you can’t, you can at least solve one common aspect of poverty: insecure, poor-quality, and unaffordable housing. The belief that you can solve or alleviate poverty through “social mixing” with more wealthy people is on the other hand a bizarre hocus-pocus, a usually unchallenged but insulting and meaningless statement. Despite this, however, Concrete Paris was a wonderful reminder of what is actually possible when building housing for ordinary people, and of what documentaries can still do. I can’t wait to one day take the RER to see some of it again.