If you work in or are otherwise interested in the New York real estate market, chances are you can point out the lines that separate all the Manhattan neighborhoods on a city map. While some neighborhoods are marked with somewhat vague boundary lines, others, such as Tribeca and SoHo, are clearly demarcated, and oftentimes they mark off city zoning areas.  The Upper East Side also has strict boundaries to the west, where it meets Central Park, and to the north, where 96th Street marks the cutoff. But now some realtors and city planners are playing with the idea of extending the northern boundary of the Upper East Side to include new luxury condos for sale in the high 90 and low 100 Streets--currently condos in East Harlem.

The primary impetus for this idea is the success of three high-end condo buildings that are officially located in East Harlem, but are being marketed and sold to a clientele traditionally associated with the Upper East Side. 4 East 102nd Street is a 42-story building filled with luxury Manhattan condos for sale. 1212 Fifth Avenue is another building, located next to Central Park on 102nd Street, that offers numerous amenities, and the oversized prewar-style condos associated with the Upper East Side. The third building is 1280 Fifth Avenue, all the way up at 109th Street, but perhaps the most luxurious of the three. This building is owned by development firm CORE, which has been very vocal about adjusting the Upper East Side’s northernmost boundary. CORE CEO Shaun Osher recently told a Manhattan real estate blog that “96th Street is an antiquated border that once denoted the northern boundary of the Upper East Side. Central Park is just as lush and green above 96th Street as it is below, and the architecture is equally as impressive.”

The New York Times looked at the shifting border question back in August, and noticed that people who once wouldn’t have considered moving above 96th Street are now starting to do it. The Times concluded that “as people of means continue to crowd the city, those lines have been shifting.”   

The continued development of Mount Sinai Hospital is another factor in a possible boundary shift. The hospital itself is located between Madison and Fifth Avenues and 98th and 101st Streets.  And it has been extending itself into the high-end condo market. In fact, it owns 4 East 102nd, and the first 12 floors of that building are devoted to medical office space. Mount Sinai also bought a 15,000 square foot lot at 14-20 East 103rd. They haven’t announced any plans to build, but if they did invest in residential real estate, it wouldn’t be their first foray into the market.

There are also signs in the commercial market that the demographic is changing. The high-end grocery store Fairway recently opened a store in Carnegie Hill on 86th Street. And there is a new Target and a new Costco are in lower East Harlem.

One major obstacle towards changing the boundaries of the Upper East Side is the way the school districts are set up. Currently the Upper East Side is in School District 2, along with much of affluent Manhattan. East Harlem is in District 4, which is home to overall less desirable schools. The district line between the two is on 97th Street, and if developers really wanted to entice upper crust families north, they’d likely have to get the Department of Education to extend the district boundaries first. That said, P.S. 171, the district of which stretches from 98th Street to 106th, is widely considered one of the best non-charter schools in District 4. 4 East 102nd Street and 1212 Fifth Avenue both fall inside these boundaries.

This kind of neighborhood boundary shift is not unheard of. Before the 1960s the Lower East Side stretched all the way to 14th Street. But agents and city planners wanted to separate the part of the neighborhood above Houston--the more affluent side-- from the part below. They successfully petitioned to make that part of the East Side into its own neighborhood that became known as the East Village. The micro-neighborhoods Clinton inside Midtown and NoHo inside the Village are more recent examples of this trend. It remains to be seen whether or not the Upper East Side will officially stretch northward anytime soon, but it is undoubtedly clear that that part of Manhattan is evolving, and doing so fast.