Revenge and heartbreak have long been motivating factors for selling a home and building a bigger, better one. When Henry T. Sloane, heir to the W & J Sloane furnishings company, built his first mansion in 1887 on Manhattan’s Upper East Side, he and his wife, Jessie, entertained New York’s elite with lavish parties.

Seventeen years later, their union ended in a bitter divorce with Jessie marrying another man five hours after the decree was issued. Sloane retained the home as well as full custody of their two daughters, who were banned from seeing their mother until they were 21.

While Sloane never remarried, he turned his passion to a new love: a 19,000-square-foot French Gothic–style mansion realized by C.P.H. Gilbert, star-architect of the times. Gilbert built more than 100 large homes in New York, many located on Manhattan’s gold coast—the strip of land that runs between Fifth and Madison avenues between East 62nd and 96th streets. Although many of Gilbert’s limestone masterpieces have since become museums, apartment buildings, or rubble, his signature—which has 11 wood-burning fireplaces, 15 bedrooms, and 17 baths, as well as hand-painted murals and numerous architectural details—built for Sloane in 1905, remains nearly intact and is currently on the market for $64 million (www.brownharrisstevens.com).

Such decadence seems inappropriate with today’s waning economy and sinking housing market, but in Manhattan, the super-high-end luxury segment has kept sales prices on the rise. During the first quarter of 2008, Manhattan posted a 318 percent increase in the number of closings over $10 million compared to the first quarter of 2007, according to a market report by ValuExchange. These high-end closings helped boost the average price for a Manhattan apartment by 47 percent to a record $1.69 million.

Properties such as the Sloane mansion and a Park Avenue carriage house built in 1890 and reinvented in 1976 as an early postmodern design by architect Robert A.M. Stern, currently listed for $33 million, are so rare and unique that buyers are willing to pay a premium for them, says Paula Del Nunzio, senior vice president of Brown Harris Stevens, who represents both listings. "These properties cannot be re-created," she says. "They are rare, beautifully located, and hold their value, even as the stock market jibes around. They have sensibility and a style of construction that no condo can have."

Large historic properties may be rare, but trendy and contemporary new condominium projects are prolific in Manhattan. Overall, the development sector of the real estate market is holding its own—boasting a rise in sales price for all sizes of apartments from the fourth quarter of 2007 to the first quarter of 2008, with properties in the four-bedroom-plus category posting the highest gains. To distinguish themselves from the crowds, some developers are forging their own paths by sharing a niche for smaller-scale projects that deliver large homes, groundbreaking architectural designs, and amenities that cater to the specific needs of buyers.

Flank (www.flankonline.com), a Manhattan-based residential design and development firm, specializes in small-scale projects with large apartments that bridge the gap between old and new by mixing cutting-edge contemporary style with traditional layouts. At 441 East 57th Street (www.441east57.com), the 15-story structure’s glass and patterned skin facade evokes the look of the brick buildings prominent in the historic Sutton Place neighborhood. Inside, the project offers seven two- to four-bedroom residences (ranging in size from 1,650 to 3,400 square feet), including four duplexes, one triplex, and a penthouse (priced from $2.795 million to $7.1 million), all tended daily by Lindquist Agency’s white-glove home cleaning service.Downtown, along the cozy cobblestone streets of the West Village, 385 West 12th Street (www.385west12th.com) features four townhomes, six full-floor apartments, and two duplex penthouses ranging in size from 2,526 to 4,382 square feet (priced from $5.795 million to $13.5 million). The three- and four-bedroom residences have eat-in kitchens, formal dining rooms, family rooms, a master bedroom with outdoor space, and living rooms with fireplaces. "Kitchen, dining, and living all in the same room is big, but not so great—the only time you can be alone is if you hide in the bedroom," says Flank’s managing director, Tim Crowley. "People have many moods and mind-sets; they need multiple places to occupy."

Josh Guberman and the Core Development Group are taking a boutique approach to development. Their new Lux 74 (www.lux74ny.com), located on the Upper East Side, holds just 12 residences, ranging in size from 538 to 5,900 square feet (priced from $685,000 to $8.2 million). A slew of interior features, including custom outdoor kitchens, plasma TVs, and radiant-heat flooring, all aim to keep occupants comfortable.

While focusing on interiors is the priority for some, other developers are pushing the design envelope with big-name architects and contemporary lines intended to garner attention from the street. Five Franklin Place (www.fivefranklinplace.com), a 20-story Tribeca project of 55 homes ranging in size from 1,200 to 3,400 square feet (priced from $2 million to $16 million) plans to do both. Surrounded by the historic stone and cast-iron buildings the borough is known for, the new building stands out with an atypical facade wrapped in reflective black metal ribbons of varying widths. Dutch architect Ben van Berkel of UN Studio designed the undulating forms to serve a functional purpose, providing privacy while maximizing light and views.

In West Chelsea, cantilevering over New York’s High Line—a former industrial rail line that will be converted into a public park—HL23 (www.hl23.com) sets forth an ambitious combination of cutting-edge design, one-of-a-kind apartment layouts, and a big-name architect: Los Angeles–based Neil Denari. Draped with shifting steel-framed forms and a glowing patterned steel skin, HL23’s reverse tapering profile hopes to stand out as a piece of architectural art among a neighborhood rich with galleries. "Our design is creative, but it is also technical and precise, like a fine Swiss watch," says developer Alf Naman.

The project will include nine full-floor residences, a duplex penthouse, and a duplex maisonette with a private garden at the building’s base. Units will range in size from 1,850 to 3,587 square feet (priced from $2.65 million to $10.5 million). In addition to being an interesting place to live, HL23 will also be a healthier environment if it receives the Gold LEED certification that Naman is striving toward. "Sustainability is the future," he says. It’s a criteria, along with location and design, that New York buyers have added to their checklists.FACTS & STATS

KNOW YOUR NEIGHBORHOOD
Manhattan is divided into three areas—uptown (above 59th Street), downtown (below 14th Street), and midtown—with dozens of distinct neighborhoods all offering different vibes. Determining where to settle requires more than a look at a home’s interior, it takes some soul searching. While traditionalists flock to the Upper East Side for its posh private schools, museums, and designer shopping, creative types will find their place in neighborhoods such as SoHo, Chelsea, and Tribeca.

GOING GREEN
New York is arguably the greenest city in America, offering 52,938 acres of parks and open space. Central Park is Manhattan’s most famous public oasis, while the Hudson River Park, on the southwest side of the city, delivers water views. Manhattan’s only private park, Gramercy Park, is accessible by key to residents who live in the surrounding buildings.

REALTY CHECK-IN
The recently renovated Plaza Hotel (www.theplaza.com) is the source of some of Manhattan’s priciest real estate transactions, including more than one residence selling in the $50 million range. Newly refurbished, the Mark Hotel (www.themarkhotel.com) currently lists its penthouse for $60 million, while the Pierre Hotel penthouse is listed at $70 million.