March 2019


by Don Friedman on March 18, 2019

One of the archetypical New York buildings is the “dumbbell tenement,” which was named after its shape, not its occupants or owners. It’s worth looking at what these buildings are and why the gradual reduction in their numbers is not a bad thing.

That’s the corner of 19th Street (left) and Eight Avenue (right), looking east. (As always, click on the picture to enlarge it.) I want to discuss the five-story building just east of the one-story empty corner retail building and the two  five-story buildings that are three buildings south of the corner (one with Murphy Bed Express in the ground-floor retail space, the other with the Square Deli). These can best be described as “partial dumbbells,” but they illustrate the issues nicely.

The basic problem is that NYC lots tend to be narrow (along the street front) and deep (perpendicular to the street) and that, until the 1900s, the majority of residential buildings covered one lot. The standard lot is 25 feet by 100 feet (7.6m by 30.5m) but a lot of rowhouse lots are narrower because developer bought a bunch of lots and redivided them. If you had four standard lots, you could combine them into one big 100 foot square and the redivide them into 5 lots (giving 20 foot wide houses) or 6 lots (giving 16 foot, 8 inch wide houses). Tenements typically were one standard lot wide but could be narrower. In order to fit more people into a tenement, you want to construct the building deeper, but with windows only on the front and rear facades, minimizing the size of the rear yard meant that a building had extremely limited provisions for light and air.

Someone had the bright idea of carving away at the sides of the building – the windowless lot-line walls – to create air shafts that were ambitiously called “light courts.” This idea was enshrined in 1879 in what has become known as the Old Tenement Law, which required that every room have a window to the outside, even if it was only in one of those narrow shafts. It’s worth noting that, prior to the 1879 law, it was legal to have interior rooms without windows. If you carve out a shaft on each side of a rectangular building, the building plan is shaped like a dumbbell – wide at each end and narrow in the middle – and the building type got a nickname. Narrower tenements might only have a shaft on one side, leading to the partial dumbbell shape I mentioned above. Let’s look at the examples on an 1895 map:

North is up the page, Eighth Avenue on the left, West 19th Street at the top, and West 18th Street at the bottom. The numbers written in the street are the addresses and the numbers written in the corner of each building are the heights in stories. The three buildings I mentioned in the photo are 278 West 19th Street, and 168 and 170 Eighth Avenue. For 278 West, you can see the deeper shaft in the middle and the entire rear portion is slightly narrower, so that there could be side-wall windows. The problem was that most of those extra windows originally faced another brick wall less than three feet away. The demolition of the top two stories of the corner building has opened things up a bit, but that corner could be built higher again at any time. In 1895, 168 and 170 were on a single lot, showing how developers would combine and redivide lots. Again, they have narrow side “yards” in the rear: 170 facing south toward 168, and 168 on both sides. If you live in the rear of either of those buildings, a bunch of your windows face the other building very close by.

Take a look at 251, 237, and 235 West 18th Street to see the classic dumbbell shape.

It took 22 years to get the law replaced with what’s called the New Tenement Law, which encouraged combining lots and creating real light courts. But the city is stuck with tens of thousands of these buildings with horribly inadequate windows. They were cheaply built and many are past the end of their useful life spans, but they serve now, as they did when built, as effective ways to squeeze a lot of people onto single lots.


March 17, 2019

Sometimes you just don’t need the old doors any more. That’s the side facade of the Joyce Theater. We’ve got three infill areas of brick: The former ordinary door a few feet to the right of where the fancy front-facade veneer ends. The door was a step up from the sidewalk and the granite step […]

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Hidden Oddity

March 16, 2019

That’s the demolition of a small commercial building on the Upper West Side. Nothing remarkable – I stopped and looked only because I used to live in the neighborhood and must have walked by this budding a few thousand times in the late 80s and early 90s. I was surprised to see that the roof […]

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March 15, 2019

Engineers share one trait with large-animal veterinarians: when we want to see our subjects in person, we have to go to them because they can’t come to our offices. “The Building Inspector as Action Hero” in the New York Times discusses two issues: the importance to the safety of NYC of having tall-building facades inspected […]

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The Thrill of Conformity

March 14, 2019

It’s not often that obscure engineering criteria make it to the op-ed page of the New York Times, but it happened recently with regard to “concrete masonry units” also known as CMU also known as concrete block. “The Joy of Standards” by Andrew Russell and Lee Vinsel is about the way that modern technological system work […]

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Elmina Wilson

March 13, 2019

I happened across a link that led me to an article about Elmina Wilson at the website for the Iowa State University College of Engineering. I had never heard of her, but her bio is impressive. After getting her BS and MS in Civil Engineering (1892, 1894) at Iowa State, she then taught there for seven […]

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Playing Detective

March 12, 2019

Are you a college student or recent grad pursuing a career in #engineering? Visit DOB's table at the Manhattan College Spring Career Fair tomorrow, 3/12 1pm-4pm in the Bronx. And check out @DCAS #civilservice exams for info on Engineering Intern tests — NYC Buildings (@NYC_Buildings) March 11, 2019 First, the DoB can always […]

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Art Imitating Life

March 11, 2019

Gotham City, where Batman resides, has been a funhouse-mirror reflection of New York for 80 years. Even the name is a reference to New York. Gotham is dark, with narrow alleys fronted by ornate (possibly over-ornate) tall buildings. The ledges and roofs of those buildings, of course, give Batman a place to stand and look […]

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A Constellation

March 10, 2019

The NYC Department of Buildings has released another on-line tool. This one provides a fast summary of permits, complaints, inspections by the DoB, violations, and construction accidents for every building in the city, accessible by a map. If you click on the screenshot above, you’ve got the entire city, as I zoomed way out. I […]

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Visible A Long Way Off

March 9, 2019

I was up on a roof in Queens on Thursday. In addition to freezing my nose off, I took the picture above. If you click on it and zoom in, you can see the Manhattan skyline off in the distance. How far off? 1 World Trade Center, the tallest of the downtown group of towers […]

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