What Is a Duplex Apartment in NYC?

Real estate terminology can be hard to decipher — for example, what the heck is a maisonette? That might lead to you questioning another confusing term, what is a duplex apartment? A recent search of NYC and northern New Jersey listings that include the word “duplex” brought up nearly 1,700 sale listings. But what makes these units different from other apartments with additional levels? Here is everything New Yorkers need to know about this distinctive apartment type.

What Is a Duplex Apartment?

While it’s unclear how duplexes first came to the NYC real estate market, they did inspire headlines when the last luxury prewar apartment building hit the market in the 1930s. The building located at 19 East 72rd Street housed more duplexes than any other floor plan type. So what separates a duplex apartment from other multi-level units spotted on StreetEasy? Here are a couple of guidelines:

First off, a duplex apartment is a two-floor unit connected by stairs or an elevator. Sometimes the lower level is a basement.

Second, both floors must have a legal minimum ceiling height of 8 feet. For example, an apartment with a loft bedroom with a ceiling height of 5 feet is not a duplex, even if it has stairs.

You might see the term maisonette used when describing a duplex. But, here’s the thing, a maisonette could be a duplex, but it also has a private entrance from the outside, while duplexes do not. What about split-levels? Apartments in this category have multiple floors connected by staggered and short sets of stairs.

Are Duplex Apartments Easy to Find?

Although available as rentals, co-ops, and condos, generally, duplex apartments are relatively rare. They represent a very small percentage of available listings: less than 9% of sales and less than 4% of rentals. You may also be surprised to know that the demand for the unique layout isn’t very high.

“Duplex units are not a popular trend given that most have stairs rather than elevators,” says Agent Karen Kostiw of Warburg Realty. “Stairs in apartments eliminate a large demographic from purchasing an apartment given their lack of easy of use and hazards (i.e., falling).”

Plus, it’s cost-prohibitive for builders. So, newer ones are not as likely to hit the market, adds Frederick Warburg Peters, CEO of Warburg Realty.

With that in mind, buyers are more likely to find duplexes in neighborhoods with more prewar constriction like the Upper East Side and Central Park West. In some instances, if someone wants a duplex in a building where they don’t exist, the person can buy two apartments and combine them. According to Kostiw, if purchased early on in the development process, having the sponsor combine them can be part of the negotiation.

Pros and Cons of Duplex Apartments

As with any real estate purchase, there are always pluses and minuses to consider. Here are the pros:

More room: Of course, single-floor apartments can be larger square-footage wise. But having two floors is going to give more of that house-like feel. And they are exceptionally roomy if you have two floors of equal size.

More privacy: Two floors, especially if the bedrooms and living areas are separate, means there’s more space for people to spread out. For example, parents can entertain downstairs while the kids sleep upstairs.

More affordable than a townhouse: If you’re wanting single-family style living without the price tag, a duplex is a good option price-wise. A one-bedroom duplex in Yorkville is just $690K, where a townhouse in the same neighborhood asks $7.99M.

Access to amenities: Since duplexes are situated within a larger building, you would have access to any communal amenities available.

Here are the cons:

Managing stairs: Spiral staircases are not uncommon in a duplex as they are space-saving. But they can be more treacherous for some. “This type of staircase is not for anyone who is not steady on their feet or for use by small children,” says broker Gerard Splendore of Warburg Realty.

Finding a sensible layout: “The first question you should ask yourself is whether or not the layout makes sense for you,” says agent Mihal Gartenberg of Warburg Realty. “For example, where are the bathrooms located, and are they easy to access in the middle of the night? There are cases where the bathroom is on a separate floor to the bedroom.”

—