Le Corbu.

Le Corbusier's unites d'habitation have been reviled as some of the worst housing types this century. Writer Lesley Hussell and photographer Paul Raftery, both residents, explain that (unlike most successors and imitators) the first unite still works well and is loved by its inhabitants.

Le Corbusier's Cite Radieuse stands like a beached ocean liner between the sea and the hills that ring Marseilles. Once despised and now revered, this national monument engagingly fulfils two complementary roles: a shrine for visiting architects and their pupils, and a backdrop to the daily lives of its 1500 inhabitants.

A magnet for the bourgeoisie of this truculent city, it is the most successful of Le Corbusier's 'machines for living in', having been transformed en-route from a novel scheme to house the poor into an urban version of the village idyll that burns in every Frenchman's heart. The old-fashioned community spirit and joie de vivre engendered by this concrete block set it apart from mundane metropolitan flat-dwelling.

Apartments are not advertised in estate agents' windows. Whether the aim is to buy or to rent, the only way to climb aboard is by word of mouth, coupled, if possible, with that most Mediterranean of business and social tools, 'le piston', or who you know. It is not a question of bribes and skulduggery, simply that the flats are now so popular that they change hands within days at prices which are above average for Marseilles: rents of [pounds]600 a month are typical for a 100 m sq apartment and they sell for [pounds]100 000.

The irony would not be lost on the critics who derided the project during construction as a 'slum', nor on the low-income families for whom it was originally intended but who refused to move into so strange an edifice and christened it colloquially 'la Maison du Fada' - the Madhouse.

State employees were the first occupants when the building opened in 1952, but gradually the 337 apartments have been colonised by liberal professionals like teachers, doctors, engineers, scientists, journalists and social workers.

They revel in its unconventionality: the third-floor shops, hotel and restaurant, the splendid roof terrace, the double-height rooms, the bright primary colours. And as the handful of ageing original residents potter around the gardens outside, a new generation of toddlers plays in the eighth-floor infants' school. Still rather mistrusted by the population at large, 'Le Corbu' remains one of the city's proudest talking-points.

A WEEK IN THE LIFE OF LE CORBU

MONDAY, 6.30 AM: The third-floor bakery opens for business and the building stirs sleepily. Children in pyjamas are sent to buy croissants, early dog-walkers head out of the lobby and the night security guard clocks off his shift. Little by little Le Corbusier comes to life. The first class of the day begins in the roof-top gym and grocer Bernard Perret sets up his fruit and vegetable stands.

A couple of tourists are breakfasting in the bar-restaurant after a night in one of the hotel's 25 rooms, which offer an authentic experience in cell-like, plain Corbusian living but are sadly devoid of original furniture, all stolen over the years and replaced by grim melamine. The hotel guests are mostly architects and students, and as they photograph and note each facet of the building, it is open to question whether it is the inhabitants who play the part of zoo animals or the visitors themselves.

MONDAY AFTERNOON: Eric Broquere, a pharmacist and writer, is alone on the roof terrace, wandering between sculpted concrete funnel vents and a stepped stage. 'This is the most inspiring part of the building. It is the perfect place to meditate, walk and dream, high in the sky amid sculptural forms. It was designed as a meeting place yet one can also find exquisite solitude here, it allows a remarkable synthesis of exchange and contemplation.'

TUESDAY AM: Martine Ricoux, headteacher at a private Catholic school, is enjoying a day off at home. Before she first entered Le Corbu, she had no desire at all to live there. Marseillaise born and bred, she knew it only by reputation - 'fada' - and its architectural significance was of scant interest. But after visiting a friend, she was converted. 'It hit me immediately: the warmth, the atmosphere, neighbours dropping by. It felt special, a world away from the curtain-twitching small-mindedness of other apartment blocks. I loved the wood floor and fittings and, above all, the fantastic view. When I look out at the shimmering Mediterranean and the little white boats, it truly makes my heart sing.'

Her flat, like the majority, has double aspect: over both hills to the east and sea to the west and so enjoys spectacular sunrise and sunset views all year round one of the architect's most appreciated inspirations.

TUESDAY AFTERNOON: clearing tables after a hectic lunch session, Jean-Marc Sialelli is tired but in good spirits. He and his wife Brigitte took over the bar-restaurant in January and have revitalised it. Cheerless and empty under previous management, it now hums with activities like a Chinese calligraphy class, couscous soirees and something Le Corbusier, no matter how visionary, could never have foreseen: break-dancing sessions.

WEDNESDAY AM: as France Emran strolls along the third floor, she passes a series of empty windows where once were a florist, butcher's and hairdresser's. The recession hit hard even in this relatively prosperous enclave and the latest victim is an art gallery which shut after a brave attempt to provide all imaginative service that the local hypermarket could not beat. With little passing trade and higher prices than city chain stores, the 'street' ironically mirrors the plight of hundreds of French villages and rubs a little gloss off the idyll.

WEDNESDAY 6PM: Bernard the grocer often has elderly pioneer residents complaining that things aren't what they used to be. 'Those who have been here for 40 years think Le Corbu belongs to them,' he says. 'They try to keep the 1950s atmosphere going with their bridge club and get-togethers but they refuse to make any concessions to youth. The roof theatre and cine club would do really well if they were advertised outside to attract more people, but the old guard drag their feet because they're afraid of being invaded. They like the idea of concerts and parties that foster Le Corbusier's community ideal, but when they happen they hate the noise and ban any more for months.'

THURSDAY 9AM: The infants' school has three classes of 30 pupils aged from two to six, mixing outsiders from the local quartier with children who live in the block. Parents believe those from Le Corbu stand out. 'They are more independent, freer spirits, better pupils but more of a pain too,' smiles one. Allowed to roam the building alone, call on friends on different floors, ride the lifts and play in the gardens without an adult in tow - because all neighbours will keep an eye out for them - they quickly become self-sufficient. 'I've sometimes looked after six at a time after school,' says one father, 'and shared responsibility for them means they soon begin to see the world through their own eyes, not their parents'.'

THURSDAY 4PM: Thanks to her job as a childminder, Annie Castay spends most of her day in, on and around the building and knows it better than most, cherishing the peace and security it affords. 'Ferrying kids to and from school is just a case of taking the lift; afterwards we go to the paddling pool on the roof in summer and the playground in winter. I can nip along for groceries or a coffee whenever I want and the little ones tricycle along the corridors with me. It is perfect because everything is centralised.'

FRIDAY 11AM: Margot Marananchi explains how she squeezed her four children, now aged eight to 19, into Le Corbu: she and husband Dominique bought two neighbouring fiats and demolished the dividing walls. They now have an extraordinary double-width double-height living area as well as four narrow kids' bedrooms. The conversion was carried out over nine years, losing the extra staircase, altering bathrooms and stripping off plaster to reveal the bare concrete underneath.

Le Corbusier designed 23 variants of his basic apartment model, from bedsits to a couple of homes intended to house up to a family of 10, albeit in extremely cramped conditions. The average Type E format has kitchen/living room, main bedroom, two children's rooms, bathroom and shower cabin on two floors, going either up or down from entrance level.

Now the variations are endless: mezzanines have been extended to give more space, destroying the double-height idea, while traditionalists have installed carpet, flowery wallpaper and antique furniture. Yet plastic kitchen units fitted by some 'modern' residents in the 1970s to replace the clever 1950s cupboards are now being torn out to be replaced in turn by copies of the original design.

FRIDAY 5PM: Evelyne, the gym instructor whose classes resemble army work-outs, is taking a lethargic group through their paces. There are regular exercise sessions in the roof-top gym, as well as body-building apparatus, a sauna and judo classes. Rates are reduced for Le Corbu residents, who arrive by lift with no extra exertion, but a 300-metre running track around the roof terrace is free for all-comers. As the gym class pull and push, the Mistral whistles ferociously around the building. It will be a noisy night as the wind howls incessantly, battering windows and knocking plant pots off balconies.

SATURDAY 10.30AM: The weekly women's coffee coven gathers in the bar for an hour of laughter, gossip and complaints. They discuss men, films and cockroaches, the insects having infested the building soon after Le Corbusier endowed it with generous ducts and ventilation passages. Indeed, this 'dream machine' is not immune to the everyday problems played out throughout France and Europe at large: a teenager is being terrorised by an outside gang demanding money, a suicidal father leapt to his death from the second floor.

The women's network is quick to react when someone needs a favour or advice, however, and is octopus-like in its range of useful contacts. A Barcelona professor interrupts the group to ask if anyone could show his students around an apartment. An hour later, 97 Catalans are being given a guided tour of the Broqueres' flat by Eric's journalist wife Joelle. When all that is left are their dusty footprints, she says: 'We feel proud to live here and we're happy to share it'.

SATURDAY 10 PM: A summer jazz evening brings a hundred residents and guests together on the roof to watch a local group. Le Corbusier imagined the Cite Radieuse as a temporary haven: young couples would arrive then move on as their families grew. In fact it is the entertainers like tonight's musicians who are only passing through, while many families have stayed more than 20 years, some with three generations in the building.

SUNDAY MIDDAY: People spill out of the building heading for country lunch, an afternoon on the beach or perhaps a trip to the city's nearby Contemporary Art Museum. Le Corbu will soon be slumbering into siesta as the sun pours through the windows on the west side.

On the block's 30th anniversary in 1982, an action committee from Firminy, the 'machine for living in' near St Etienne, came to visit. Whereas 80 per cent of the Marseilles apartments are owner-occupied, Firminy had remained a low-income project unable to fund maintenance bills and is crumbling into unhappy disrepair. The committee activists used to struggling for better conditions were shocked to discover their Mediterranean counterparts 'living a life of luxury'.

The relative wealth of Le Corbu's residents does mean they can afford the [pounds]200-a-month charges levied for upkeep, working lifts and security staff, while a government-sponsored renovation programme over 12 years has just finished restoring the building to its original glory. Geographical context must, however, play a part in Le Corbu's success. Here dry rot and rising damp are unheard of, and a glimpse of the sea or the hills is often enough to lift the spirits.

SUNDAY 6PM: A gleaming white ferry en route for Corsica slips across the Mediterranean. Le Corbu, its land-bound reflection, sails towards another colourful week.