The living room in Massimo De Carlo’s Milan home, with floor and wall carpets by the artist Rudolf Stingel. The standing lamps are by Gino Sarfatti; the chairs are by Sergio Rodrigues (left) and vintage; the coffee table is by George Nakashima; the ceiling lights are by Studio Binocle and Rossi Bianchi; and the chandelier is by Paolo Venini.

Photograph by Alexis Armanet.

When you walk into the home of Massimo De Carlo, one of Europe’s preeminent art dealers, the first object to catch your eye is not especially welcoming. On the ceiling in the entryway there’s a big water stain, its edges lumpy with layers of green and black mold. Below it there’s a plain metal bucket to catch the leakage.

De Carlo, who moved into the home in 2016, knows that the unsightly stain makes visitors uncomfortable, because most of them never mention it. “They’re afraid to say anything,” he notes with an amused grin. “The house is brand new, so it’s a delicate matter. Only a few close friends will say, ‘Hey, what the hell is going on here?’ ”

The leak is actually a work of art by the Scandinavian duo Elmgreen and Dragset, first shown as part of an installation in their 2013 show at London’s Victoria and Albert Museum. (“When I saw it, I said, ‘Guys, save this one for me—I need it for my house,’ ” De Carlo recalls.) From the entryway, a few stairs lead up to the living room, where the ceiling looks just fine, but visitors might wonder why the walls are covered with the same thick purple carpet that’s on the floor, making it hard to be sure which way is up. In this case the entire room is an artwork—an adaptation of a piece that Rudolf Stingel first showed at De Carlo’s gallery a few years ago. It turns out that De Carlo’s home, as well as his multiple gallery spaces and most of the other places where he likes to spend time, is full of stuff that’s disconcerting or even destabilizing, but ultimately enriching for those people who take the time to understand it.

In the living room, (from left) Thomas Grünfeld’s Elend, 1990, a 17th-century mosaic portrait of San Carlo Borromeo, and an untitled work by Rudolf Stingel, 2007.

Photograph by Alexis Armanet.

Another view of the living room, with a chair by George Nakashima and a stairwell-elevator designed by Studio Binocle.

Photograph by Alexis Armanet.

De Carlo, 61, has a roster that ranges from blue-chip international mainstays such as Urs Fischer and Maurizio Cattelan to young L.A. painters of the moment like Jennifer Guidi. He has additional spaces in London and Hong Kong, and sets up shop at about 15 art fairs per year. But he remains a discreet and somewhat mysterious figure who grants interviews as infrequently as possible. (“I’m kind of a snob,” he jokes. “It’s a matter of survival.”) Earlier this year he got a wave of fresh attention when he opened his latest Milan headquarters in a richly ­idiosyncratic villa from the 1930s. In the renovation, De Carlo preserved the space’s quirky frescoes and pink marble accents, and many saw the move as a radical break from the minimalist white-cube aesthetic that has prevailed in exhibition venues for the past 50 years. But De Carlo has always had a thing for places with strong personalities and their own histories. At one of his first Milan galleries, a glass wall in the main room framed a sumptuous outdoor garden; the new space, designed ­during Italy’s fascist era by Piero Portaluppi and left empty in recent years, is one that De Carlo initially hoped to live in, after eyeing the building and its showstopping spiral staircase from the sidewalk years ago. An attempted purchase in 2008 didn’t go through, and by the time he finally bought it, he’d decided it should become his gallery headquarters. Since the historic facade is landmarked and De Carlo couldn’t make any changes to the exterior, he leased a sidewalk ad panel near the entrance, which now serves as the gallery’s sign.

“It was time to be innovative,” De Carlo says. “At the beginning, the idea of the white cube was an intellectual position, declaring that decoration was the enemy. Okay, fantastic—but this was the 1970s. Today we have completely different people coming to the gallery, completely different collectors, a completely different idea of the future and of the present.” De Carlo was also frustrated by the way typical contemporary galleries limit opportunities for exhibitions to develop a narrative or reveal themselves gradually. “You walk into this big space, you see everything at once, and maybe you’re overwhelmed by it,” he says. “And then you go out. Here, you have to discover the work. You do not know in one second what the artist is offering you. You need to go around.”

De Carlo’s personal history is also marked by plenty of indirect, unconventional pathways. He began his career not as a gallery assistant but as a pharmacist. For his lower-middle-class family in Padua, he explains, “it was important to have a solid job, and I didn’t want to disappoint them.” But he soon found himself moonlighting as an avant-garde music producer, organizing concerts in Padua. In his early 20s he started collecting artworks and soon afterward opened a gallery in Milan. De Carlo vividly remembers the number of pieces he sold during his first year in business: zero. “So I was working in the pharmacy at night, earning money to pay rent for the gallery space,” he says.

De Carlo in the kitchen of his home, which features Swedish Pukeberg pendants, a Tiziano Vudafieri table burned by Maarten Baas, Friso Kramer and Wim Rietveld chairs, and a 1960s table lamp.

Photograph by Alexis Armanet.

As he settles into the conversation, De Carlo’s manner becomes much warmer and his smile more playful, but his sharp, direct gaze gives you the feeling that he never quite stops sizing you up or noticing whether you’re catching his references to arte povera figures and Brazilian ­furniture designers. People close to De Carlo say his deep curiosity and unaffected charm are part of a complex magnetism that can feel like a rare reward to those who earn it. “Every time I go to see Massimo, I’m excited to just be amused by him,” says the artist Rob Pruitt, who first hit it off with the dealer during a chance conversation at an art fair, where Pruitt was pretty sure De Carlo had no idea who he was. (The artist joined the gallery shortly afterward.) “He can be gruff, but he’s a very sensitive and funny person, and there’s an electricity there that you can’t fake. You just get a charge from his company.”

De Carlo is unexpectedly candid about a few topics that most dealers avoid discussing publicly—profits, for example. “In the art world there are some hypocrisies,” De Carlo says. “I don’t think that we have to be afraid of money. Yes, we have to be afraid if money changes our attitude about seeing art. But if you’re experienced, if you are strong, if you have an idea of what art should be, money is just facilitating the process to make art visible.” These days, De Carlo notes, artists who are short on cash face much bigger hurdles than they used to. “Now you need to be visible in different parts of the world, often at the same time. And the studios of some artists are big machines. I’m not even talking about the Jeff Koonses or Damien Hirsts. Any artist who’s becoming popular needs a decent place and a team around him. He needs to pay an assistant, to pay somebody to stretch his canvases. It’s an ongoing investment to try to do your best possible work.”

Nowadays, the massive expenditures required by art fairs and blockbuster shows are squeezing out some medium-size galleries like his, while further enriching a handful of behemoths that are essentially too big to fail. De Carlo, however, isn’t excessively nostalgic about the pre-boom days, or about the old-school, Leo Castelli–style approach to selling art, in which dealers stuck to a small and intimate stable of artists of their own generation. While he still prizes a personal connection with his artists (for an opening in 1999, Cattelan famously used thick strips of tape to hang De Carlo on the gallery wall for two hours), De Carlo also employs about a dozen staffers to scout fairs and shows internationally. And today’s young artists, he notes, are savvier than ever about the business side of things. “Now, every artist knows that there is a connection between the art they make and the value of the art once it goes into the world,” he says. “It’s just reality. Do they want to talk about this? Not so much. And that’s okay—maybe that’s the reason there is a dealer.”

The gallery terrace, with a marble spiral staircase designed by Piero Portaluppi in 1933.

Photograph by Alexis Armanet.

One inevitable downside, De Carlo says, is that competition among those dealers has never been more cutthroat. No matter how big or rich a gallery becomes, there will always be rivals angling to lure away promising artists with offers they can’t refuse. (Cattelan and Stingel are two stars De Carlo found very early who have stayed with him.) “It’s a daily fight,” De Carlo says. “And as with all competitions, there is one winner and one loser. I am trying to balance my defeats. The artist wants the best, and I can’t blame them. So I’m offering them my best, and it’s working. But of course, others are doing the same.”

As the financial stakes have gotten higher in recent years, De Carlo has noticed a pervasive lack of adventurousness in the art world—especially among collectors who behave more like copycats than connoisseurs. “Art consultants are very conservative because they’re paid to suggest the right things,” De Carlo says. “Which means everybody is suggesting the same things. And then all collections are the same.”

Inside De Carlo’s new Milan home there are countless clues about the dealer’s personal interests and obsessions, but market forces seem to play no role at all. A beguiling sculptural piece on his kitchen table turns out to be a plain old potato from his refrigerator drawer; it began ­sprouting green shoots in a way that pleased De Carlo, so he mounted it on a cork from a wine bottle. (“Massimo is more like an artist than any dealer that I’ve worked with,” says Pruitt. “He’s out there, looking under stones and taking paths that other people don’t take.”) Next to the potato is a smashed car mirror that De Carlo found in the street and plans to give to the artist Diego Perrone, who uses similar objects in his sculptures. The table itself is made of charred wood; it started out as a regular piece in De Carlo’s previous apartment but was custom burned by Maarten Baas, before the designer became famous for blowtorching chairs and tables. “I was speaking with a friend who knew Maarten,” De Carlo recalls. “He said, ‘Maarten Baas is asking people to give him their furniture, and then he gives it back to them burned.’ And I said, ‘Fantastic. Let’s do it.’ ”

Stacked on the kitchen shelves are a few pieces of 20th-century ­Weimar pottery that seem unremarkable until De Carlo starts talking about them. Produced in factories during the 1920s and 1930s, after the Bauhaus school was founded, they’re hallmarks of an era when the traditional hand-painted flowers and animals of Meissen porcelain were giving way to a bolder geometric style, painted using stencils and spray guns, a new invention at the time. “And the professors there were ­Kandinsky, Klee, all these geniuses,” De Carlo says. After the Berlin Wall came down, he started buying the dishes at German flea markets for $2 or $3 each. A staffer tells me later that the dealer now has one of the biggest collections of Weimar pottery in the world.

In the gallery, segments of the original blue ceramic tile floor were restored

Photograph by Alexis Armanet.

A view of the gallery, with the villa’s original fireplace and mirror, which De Carlo preserved.

Photograph by Alexis Armanet. Retouching by Emma Finat at Pardon My French.

Back in the living room, with the Stingel carpet as a backdrop, De Carlo has hung a Lucio Fontana painting and a 17th-century mosaic of San Carlo Borromeo, among other works. Although the whole room is an installation of sorts, De Carlo says, “the interesting thing is that it doesn’t really change your experience of living here. That’s exactly why it’s so good—you use it in the same way.” He pauses and laughs. “Of course, the chairs are not so comfortable.” For the main seating area, De Carlo wanted four very different wood chairs from four different periods and places. So there’s a 19th-century Chiavari chair from Liguria, in a style that Gio Ponti used as inspiration for his iconic Superleggera pieces; a 1970s Brazilian piece by Sergio Rodrigues, spotted while De Carlo was on vacation in Rio de Janeiro; a mid­century George Nakashima desk chair; and a contemporary one by Studio Mumbai that the gallerist snapped up at Design Miami.

“For me, this is the way you build a collection,” De Carlo says. “You start from scratch with one little object, and then you buy another one. And you say, Okay, let’s continue, because this is interesting. Then you have 10, and each one is different, but all together they mean something. It should start from the experience of your life, or the experience that those objects have—their own experience. And they stay together.” De Carlo adds that the current arrangement of four chairs in the living room, much as he likes it, might change soon. “I am now looking for a fifth,” he says.