lot line windows in nyc

Buildings with lot line windows in NYC. (Busà Photography/Getty Images)

Recently, while talking to a potential home buyer about their property search, the conversation turned towards lot line windows. It’s a topic that comes up frequently and was also at the center of much discussion and debate during my own apartment search a few years ago.

What exactly is a “lot line window?” Every building sits on a piece of land, usually identified in a city tax map as a “lot.” A lot line is the boundary of that land. Many buildings, constructed for maximum size, are built all the way to their designated lot lines. If there aren’t other buildings abutting their own lot lines, windows are often installed into the lot line wall, thus creating “lot line windows.” Besides living on a lot on the corner of a street or avenue, there is likely no way to escape the lot line window conundrum.

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The Lot Line Window Conundrum

The problem with lot line windows is that if a building does eventually get constructed next door, these windows can (and must) get bricked over. The result is loss of sunlight, views, and in the worst case scenario, a bedroom or two.

In NYC, for a room to be considered a true bedroom it must have a window. More windows = more bedrooms = higher value apartment. Windows are serious commodities, which is why unit owners and developers often install lot line windows, even if they may eventually get bricked up by construction next door. It could be years, decades even, before someone builds next door, so you might as well take advantage while you can. BUT, buying an apartment with lot line windows warrants the serious consideration of any potential home buyer.

How Lot Line Windows Can Impact Bedroom Count

Check out the floor plan above. Though it is being marketed as a 3-bedroom, one of the bedrooms (see red arrow) relies on lot line windows. If a building is constructed on that side of the apartment this must turn into an office, den, or media room and the apartment as a whole will officially become a 2-bedroom instead of a 3-bedroom. When you sell, you’ll likely have take some money off your resale price. This is not a rarity. Like many NYC apartments that are not on corners, the main windows are in the front and back of the unit, but lot line windows have been installed to increase the number of bedrooms.

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Tips for Assessing an Apartment with Lot Line Windows

If you’re considering buying an apartment with lot line windows you must ask yourself the following:

  • Does the price reflect the potential loss of bedrooms?
  • What will happen to the value of the apartment if the lot line windows get bricked over?
  • Will my family still have enough bedrooms to live comfortably if the lot line windows disappear?

There are a few ways to put your concerns at rest, or at least put them in perspective. When you’re looking at an apartment and discover it potentially has a lot line issue, it’s vital to look around and get a feel for the neighboring buildings and how they might impact your building in the future. This exercise can help you make good assumptions, ask important questions, and do better research. For example:

  • Is there an empty lot or a parking lot next door? Empty lots and parking lots are prime targets for future construction sites. If there’s one in your adjacent lot there’s a good chance that it will be developed in the future.
  • A shorter building that ends below your window line usually has the right to build up. Even if the current owner has no plans for construction, they can always sell it to someone who does.
  • Is there a lot of new construction going on in the area?

Let’s look at the building with the floor plan above. As you may recall, there are lot line windows on both sides of the building. As luck would have it, there are also parking lots on both sides. Uh-oh, right? Take a look at the picture here. You’ll see that the building attached to the East side parking lot has tons of windows. It’s rare that a developer would put in so many windows in such a large building if there was concern about losing them. Now it’s time to investigate the “air rights.”

Lot line window illustration


Air Rights: What You Need to Know

Air rights are essentially the right to develop. In this particular instance, a developer bought a handful of lots. In order to protect the windows, views, bedrooms, etc. of one building, he didn’t develop the adjacent lot and transferred the air rights of that lot to the large building. So, this particular parking lot is almost guaranteed to never be developed. If you bought the apartment here, your East facing lot lined windows are safe. Thanks, neighbor!

How do you find out information about air rights? Acris, the NYC Registrar, of course! (But you’ll want to rely on an attorney or architect for verification before you plunk down millions on your next apartment.) In Acris, the air rights agreement will probably be identified as a document type of AGREEMENT or DEVELOPMENT RIGHTS.

It’s also possible that your building owns (or purchased) the air rights – chances are this will be touted heavily by the selling broker and also reflected in the sales price.

The most important lesson is don’t take lot line windows for granted – look around, ask questions, and do your research.

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