# What's the word for an unused, enclosed space between two apartment buildings?

Over a decade ago, my partner and I moved to New York City (Brooklyn). We were somewhat surprised to find a certain feature of our apartment building; where it abuts the adjacent apartment building, there is a small open space, a few feet wide. This space is fully enclosed by the buildings and cannot be accessed except by an internal access door through the basement of the buildings. No one ever enters or uses the space. It provides positioning of windows for sunlight into the kitchens, bathrooms, and central living spaces of all the apartments. We can look from our kitchen directly into the neighbors' kitchen a few feet away. An example of this space is shown from Google maps below:

For scale of the space, compare to the cars on the street. These are not very large buildings; maybe 3 or 4 stories tall, and each floor is just a single residence.

I'd like to be able to say with friends something like, "Today there are workmen doing construction in the ____ and it's very loud in my apartment!".

What's the name of this small, enclosed open-space feature between two apartment buildings?

• If this is space is a few feet, I hate to think how small your apartment is. Aug 31, 2020 at 11:02
• It is good practice for adjacent property owners to line up their airwells, so they overlap onto one airwell twice as large. However, that isn't what happened here; that entire group of buildings (14 visible) is the same development built together. They may have been built to be sold individually to future landlords, but they were built as a group by one. Aug 31, 2020 at 22:21
• That space is about 1.2 car lengths deep, kitchen to kitchen, and about 1.5 car lengths wide. A midsized American car is 14.7 ft (4.5 m), so I would estimate the space to be 17'x22' (or about 5m x 6m). That's absolutely large enough for some activities! Nov 30, 2021 at 19:59
• To be clear, I didn't use our actual building for the picture; our air shaft is smaller than the one illustrated. I measured our specific one at 8 feet wide. Nov 30, 2021 at 20:33

It's also called air shaft.

Air shaft: (architecture) A vertical (or near vertical) opening (shaft) running from a courtyard to the sky, thus allowing air to circulate to high-rise apartments or offices.
[Wikitionary]

Or air well

Air well: a court enclosed within walls and open at the top for supplying air to windows — called also air shaft.
[Merriam Webster]

There's a whole article about air shafts in NYC on 6sqft, I'll just copy-paste the relevant quote:

When exterior windows finally became mandatory in the 1880s, developers were naturally eager to comply with the city’s new building law but without losing a significant amount of building space. For at least two decades, this led to the construction of buildings with interior air shafts so narrow tenants to shake hands with their neighbors’ in adjoining buildings.
[6sqft]

Another quote from BrianWestbye's blog:

So much goes on in a Harlem airshaft. You get the full essence of Harlem in an air shaft. You hear fights, you smell dinner, you hear people making love. You hear intimate gossip floating down. You hear the radio. An air shaft is one great big loudspeaker.

Thanks to Mari Lou A for the links!

Wikipedia article on the NYC law that created air shafts

• Great, I'm picking this as the selected answer because it has multiple references specifically to NYC usage as "air shaft". Thanks to you and @Mari-LouA. Aug 31, 2020 at 3:45

What the OP describes is a lightwell. That is, however, a broader term, as it also covers (and is, perhaps, more often used for) a similar shaft within a building, i.e. for one that is enclosed on all four sides by the same building. There does not appear to be a term specifically for a lightwell of the kind that is described by the OP, i.e. one that is enclosed by parts of two separate buildings.

As the Decapitated Soul's answer on this page points out, such an architectural feature can also be called an air shaft. The choice between the two terms presumably depends on whether one regards illumination or ventilation as the principal benefit that it provides.

A defining characteristic of a lightwell is that it is too narrow for its bottom to be used or any significant purpose. That distinguishes a lightwell from a courtyard, which is large enough for its bottom surface to be used as a yard. The distinction between a lightwell and a courtyard is not precise, but it probably has more to do with the ratio between its width and the height of the building, than with the width itself.

• The closest term... I think it is the correct term: en.wikipedia.org/wiki/Lightwell "In architecture, a lightwell, light well or air shaft is an unroofed external space provided within the volume of a large building to allow light and air to reach what would otherwise be a dark or unventilated area." Upvoted. Aug 29, 2020 at 21:00
• Yes, absolutely correct. A light well (or lightwell) is an architectural feature that can be used to take natural light into the interior spaces of a building. It takes the form of a vertical shaft within the volume of a building that typically penetrates from roof level down to lower levels, allowing the transmission of natural light to areas that would otherwise require artificial lighting. Designing Buildings. Aug 29, 2020 at 21:32
• If they extend down to the ground, they're called "prairies" in the Chicago area. Aug 29, 2020 at 22:02
• Do locals use the term light well? Would "they're doing construction in my lightwell" be understood? The air shaft answer appears to give examples of common use, but light well feels like a term only used by architects. Aug 31, 2020 at 2:19
• In Middle Europe in early 20th centuty it was common to built houses with such spaces. The German word "Lichthof" was used not only in Austria and Germany but also in countries of former Austro-Hungarian empire. This word was and still is used in some Slavic languages (e.g. Croatian). Aug 31, 2020 at 12:15