"I'm sorry, but most of the activities are finished for the day," theman says. "Come back tomorrow. We have 'Coffee Time' at 10 a.m." I'm signing in at the Piccadilly Community Center's reception, which doubles as its canteen. Leaning on one of the vinyl-coated tables, two guys in checked shirts are having milky tea and biscuits. There's a stand full of promotional leaflets: "Day Trip to Paris," "Discover the Internet." I have to insist: "Can I at least drop in to the 'Singing in Spanish' class?" Having promised that I wouldn't bother anyone, I enter aspace labeled "The Ballroom" where half a dozen elderly Hispanic ladiesare rehearsing folk songs. They are totally engrossed in their lesson, but not in a theatrical or demonstrative kind of way. They are simply enjoying being there, perfecting their ensemble under the attentive guidance of their young teacher.

Initiated by the highly unpredictable Swiss artist Christoph Büchel,the Piccadilly Community Center offers a full schedule of courses ranging from "Life Drawing" to "Mother and Baby Yoga" — all improbably set up within the blue-chip confines of Hauser & Wirth's gallery on Piccadilly. Several charities, including Age UK, WestEnd Children's Center, and Open Age, were invited to use thepremises built inside the space, and according to a gallery representative they have readily accepted the offer. "We have had a verypositive response from members of the community and beyond," she said. "People attend the classes from all over London, eager to utilize the free room here and classes taking place in an ideal location in central London."

On my way upstairs, I pass by the counseling and gym rooms. Daubs hang on the institutional pink walls and plastic flowers cram every corner. The installation is so convincing that I almost forget the dozens of polished exhibitions I've seen in this gallery. The carpet seems to bearthe marks of generations of orthopedic slippers. Pranksters have drawn afunny face on the meeting room's white board. In the prayer room, cheapstatuettes evoke vague ideas of universal spirituality. Going through these banal corridors doesn't feel like being on a film set: the experience is more like being thrown into the shooting of a real-life documentary.

Büchel is renowned for his immersive, hyperrealist installations. At Glasgow's Tramway last year, he set up a lugubrious laboratory inwhich a crashed aircraft looked like it was halfway through a dismantling process. Passengers' possessions were all individually labeled, while rows of seedy jails alluded to some sadistic experiment in progress. Like Robert Kusmirowski or Mike Nelson, Büchel could be seen as an heir of Ed Kienholz, but the amount ofdetail and level of accuracy involved in his practice distinguish him both from this artistic lineage and from his peers. In each installation, every single crack of paint is carefully composed to appear accidental — and the artist doesn't take this lightly. For four years, he was enmeshed in a bitter legal battle with MASS MOCA, which attempted to exhibit his unfinished installation "Training Ground for Democracy" against his will. Büchel's practice is far too precise toallow this kind of approximation — and the U.S. Court of Appeals in Boston finallyruled in his favor in 2010.

Büchel's open collaborations with non-artistic organizations further blur the boundary between the authentic and the made-up. At "Secession in Vienna," he invited a local swingers club, Element 6, to stageorgies by at night in the premises built for his show in the museum — atongue-in-cheek response to the scandal caused by Klimt's "pornographic" pictures at the turn of the century. In London, both the community center's users and exhibition-goers visit during daytime, which adds greatly to the installation's impact. Inhabited, the environment is not only an artistic proposition: it becomes the very object it is supposed to mimic. Büchel's piece might be the ultimate readymade, a fully functioning chunk of real life shoehorned into a gallery space.

A community center like this could be found pretty much anywhere in the country — except, perhaps, on the glitzy thoroughfare where it is located today. The piece functions as a "reality-check" for the polishedimage Central London is actively cultivating. On the top floor, there'sthe Geranium Charity Shop for the Blinds, and right across the room a Conservative Party Archive, which sells mugs and posters bearing Tory slogans, from "Smoke Baldwin's Security Mixture, Vote Conservative" of 1929 to the infamous 1997 "New Labour, New Danger."

Büchel has never been afraid of mixing art and politics. Three years ago, he turnedKassel's Fredericianum into a fair showcasing all the registeredpolitical parties in Germany, including the right-wing NPD. At London'sHauser & Wirth, his inclusion of grassroots political campaigning gives the installation palpable currency. The Piccadilly Community Center enacts the "big society" ideas put forward by the coalition government while underscoring the need for social services, threatened by the same government's erratic "austerity measures." When I finally left, the Spanish ladies had stopped singing.