Last New Year’s Eve was my first in Berlin. We live at the edge of Wedding, a neighborhood just north of the city center that, counter to what its name evokes, is gritty and sprawling, studded with public housing and betting parlors. A photo of our block from August, 1961, when it was part of West Berlin and the East Germans began construction of the wall, shows a squat row of cinder blocks beneath a canopy of barbed wire, running perpendicular to our street. The wall, still in its earliest stage, is only about chin high, and a flock of G.D.R. troops riding in an open-air jeep is visible on the other side. Today, the neighborhood is mostly populated by a mix of descendants of Turkish guest workers, older Germans, and some young couples seeking relief from higher-rent neighborhoods. Saint Sylvester’s, the feast day that falls on December 31st, is still considered a family holiday; some restaurants close, and many people celebrate at home, eating raclette, which I was embarrassed, in my American lack of refinement, to discover is different from fondue. Starting at around 11 P.M., the crack of fireworks—purchased illegally in Poland—was so loud and so rapid in the street outside our apartment that it sounded like an air raid. The entire sky was illuminated, as if by a giant, otherworldly streetlamp. There was so much smoke in the air that we had to keep the doors to the balcony shut, slipping outside for only a minute at a time to take videos on our phones. It was, at once, grand pageantry and a kind of private show.

By the next Saint Sylvester’s, there may be more than a thousand new residents on our block. In the past year, on a slim three-acre strip of land that hugged the wall, a dozen new buildings, which will contain more than seven hundred new apartments, have sprung up, part of a development called So Berlin. When I first visited Berlin, ten years ago, the city was still recovering from decades of abandonment; there was a housing surplus, and vacant industrial buildings were still being taken over by artists, d.j.s, and squatters. But, since 2004, property prices have more than doubled; in 2017 alone, they increased by 20.5 per cent. Last year, Warren Buffett announced that his company, Berkshire Hathaway, would set up shop in Berlin with a local partner that promotes Berlin’s (relatively) low prices to international clients, who may want to cash in on potential appreciation. Moving into the city, as nearly fifty thousand people did last year, and finding an apartment is becoming as exasperating as it is in New York. Rents are rising, but not as quickly as property values: rents rose fifty-six per cent between 2009 and 2014; purchase prices rose seventy per cent. That’s the definition of a bubble.

In the former East, the government set about selling off publicly owned buildings after the wall came down. Clubs and galleries took over. It became the hip part of town with cultural capital that attracted young professionals with financial capital, and its gentrification radiated, like Brooklyn’s, slowly outward. A few weeks ago, in the far reaches of East Berlin, next to a formidable-looking Soviet-era slab-block building, I went to see a site where a developer has plans for a gleaming horseshoe-shaped condominium, with units starting at a quarter of a million dollars and going up to a million. The real-estate agent, who arrived in a black sedan with tinted windows, met me in the adjacent parking lot of a shabby strip mall, which bore a bright blue sign that read, rather unconvincingly, “Mediterranean Bistro.” The bistro was slated to be razed, but everything else would remain, staging an awkward confrontation between Berlin’s new ethos and its musty socialist past. Who, I wondered, would end up living there?

“Gentrification” is a loaded and amorphous term. As of ten years ago, apartments in various atrophied East Berlin neighborhoods had smog-emitting wood-burning stoves and shared water closets in the hallways. Most of those buildings have been updated—painted in pastels, their exuberant neo-Renaissance moldings restored—and they now make up some of the most captivating parts of the city. At the moment, Berlin is compulsively livable, with few crowds, little crime, and cheap groceries. But its reputation as a hub where artists and creative types can rent inexpensively and still afford to do as they please is eroding. Certain neighborhoods, such as Kreuzberg, another area that, like Wedding, was pressed up against the wall and became home to immigrants with few other choices, have had the hex of coolness cast upon them.

There are many regulations in place to try to control prices, but the government is increasingly outmatched by the market. In May, I went to Kreuzberg to meet Helge Peters, an academic in his mid-thirties who recently moved back to Berlin from the U.K. A week earlier, on the annual May Day holiday, Berliners had gathered in a nearby park to drink beer and smoke spliffs. I took a photo of two punks in leather vests with matching mohawks, one dyed red and the other green, who leaned in to snap a selfie. During the twentieth century, the holiday was characterized by workers’ protests, which were sometimes fatally violent. But this year, in addition to people slinking to trance and grilling bratwurst in back yards, several thousand people gathered in Kreuzberg and nearby Friedrichshain with a new mantra: “Unser Kiez, nicht ihr Profit!” (“Our neighborhood, not your profit!”)

Peters led me across the noisy Kottbusser Tor roundabout, from a Turkish neighborhood café to a small wooden hut that had been set up, illegally, by tenants’-rights activists, who named it Gecekondu, a Turkish term meaning “built overnight.” Across the street was an immense complex ringed by balconies painted a blighted orange and green. In 2004, the Berlin city government, faced with a budget deficit, sold the building to Deutsche Wohnen, the second-largest property company in Germany. The firm, which is publicly traded, is built to produce dividends for shareholders, the largest of which are financial entities. BlackRock holds a roughly ten-per-cent stake, Massachusetts Financial Services Corporation another ten, and Norwegian Bank an additional 6.9 per cent. Peters, cautious and exacting, explained to me one of the main loopholes that property companies like Deutsche Wohnen have found in German rental regulations. According to the law, certain modifications, like fixing a broken heater, are “maintenance” expenses, which the building’s owner is required to pay for. But if an adjustment could instead be categorized as “modernization,” or as an upgrade to the building, the company could raise the rents, unloading some of the costs onto tenants and increasing its revenues. Accordingly, tenants at the Deutsche Wohnen building in Kottbusser Tor went without heat for several weeks last winter, and for a number of winters before that, because the company was loath to spend money on anything that qualified as maintenance rather than as modernization. (In April, Deutsche Wohnen told the German newspaper Der Tagesspiegel that affected residents would have their rents reduced.)

Something similar appears to have happened last spring, when WIBE Real Estate Invest L.L.C., which is registered in Vienna, purchased one of the few early-twentieth-century buildings still standing in Berlin. I visited it recently, and the façade was covered with scaffolding. One of the tenants, Felix Gaedtke, led me into his vintage-parqueted, high-ceilinged living room. Two weeks after learning of the building’s new owners, Gaedtke and his wife had received a forty-page letter from a lawyer, informing them that more than ten per cent of the exterior of the building was damaged, which meant that the company was required to “modernize” it. Gaedtke took the letter to the city, which ultimately denied WIBE the renovation permit because no damage had been documented at the time of the building’s sale. “We were, like, O.K., this is great. It’s over,” Gaedtke said. A few months later, he received another letter from the company—it planned, instead, to paint the building, which doesn’t require a permit. That’s when the scaffolding went up.