Notes on 19th Century Lot Sizes

By Richard Howe

By the end of the 19th century most of the streets and avenues laid out on the island of Manhattan by the 1811 Commissioners Plan and its 1870 northern extension by the Central Park Commissioners had been opened to traffic and as much as two-thirds or more of them had been paved. The island’s rural estates had been broken up and sold after having been subdivided into building lots conforming to the blocks in the street plan. Most of the island up to about 168th Street had been densely built up, with nearly 100,000 buildings — over 80,000 of them residential — carpeting the built-up area. At least 90 percent of all the buildings on the island — and 99 percent of the residential buildings — were no more than six stories tall; the average height was about five stories: 60 feet at a nominal 12 feet per story. And at least 75 percent of the buildings were 20–25 feet wide and 60–80 feet deep. But why? Why so many buildings, and why so many in just this range of sizes?

Because a builder must acquire a property before building on it, it is tempting to assume that so many 19th century New York buildings were 20–25 feet wide simply because the properties available to builders were 20–25 feet wide to begin with. And indeed, the conventional wisdom has long held that 19th century New York building lots were uniformly 25 feet wide, a notion that may have had its source in the Reverend John Francis Richmond’s 1871 survey of New York and its Institutions, in which he stated that the island of Manhattan was at that time “by survey divided into 141,486 lots, 25 by one hundred feet each.” Richmond gave no sources for his figures, but as estimates they were surely not bad: 141,486 lots each 25 x 100 feet equates to about 670 miles of street frontage, or 335 miles with lots on both sides of the street, which is a remarkably good figure -— within ±1 percent! —- for the total available street length of about 500 or so miles on the island (the current figure is about 504 miles).

Richmond’s estimate of 141,486 lots is in fact so precise that it is hard not to suspect that he — or his unnamed source — simply assumed that city building lots were uniformly 25 x 100 feet and then worked backwards from the known street frontage to the number of lots, for in fact the entire island had not been “by survey divided” into lots by 1871. Even eight years later, Bromley’s 1879 real estate atlas showed many undivided blocks towards the northern end of the island, and it is likely that, whether actually surveyed or not, a great many of the 25 foot wide vacant lots outlined in the atlas were speculative rather than real — i.e., they had not been formally registered with the city — though it was not uncommon for the island’s rural estates to be divided up for sale into rectangular lots that were integer multiples of 25 feet in width — e.g., 25, 50, 75, 100 feet, and so on. The later 19th century big estate sales — Carman, Jumel, Morgenthau, Ward, and others — created thousands of such lots for the city’s developers to build on. But other widths were by no means uncommon — e.g., 16 feet 8 inches, 31 feet 5 inches, 76 feet 11 inches, to cite just a few examples — and in any event it is unlikely that the number of formally registered lots on the island of Manhattan was ever much above 120,000, if that.

It was also not uncommon for speculators to buy large lots, or even whole blocks of them, purely as investments, often selling them to other speculators in turn. But eventually they were bought by developers, who then subdivided them to match their building plans — e.g., dividing a single 100 foot wide lot into five lots for five buildings, each building 20 feet wide. The widths of their improved — i.e., built-upon — lots as shown in Bromley’s updated atlas of 1891 ranged from as little as 12 feet 6 inches to as much as 60 feet or more. Some of the commercial buildings were of course very wide, which brought the average width for all buildings up to nearly 30 feet, though most buildings were in the range of 20–25 feet, with 22–23 feet the most common, especially for residential buildings. So lot widths and building widths were not independent of one another, and lot widths were as much if not more the result of building widths than building widths were the simple result of prior lot widths.

Figure 1: section from Bromley’s 1891 atlas showing actual lot outlines and widths in the middle of the block bounded by Amsterdam (Tenth) and Columbus (Ninth) Avenues and by 73rd and 74th Streets. Top row widths (feet) left to right: 22, 28, 25, 25, 18, 20, 20, 20, 22, 18, 20, 20, 20, 22, 25, 25, 25, 25, 19, 20, & 19. Bottom row: 18, 17, 17, 16, 16, 16, 19, 20, 20, 20, & 21, the rest each 18 3/4. The mix of widths is typical. Key: pink = brick building; brown = stone; yellow = wood; brown + pink = brownstone; blue line is an old farm boundary (map: David Rumsey Collection).

The conventional wisdom has also long held that the supposedly standard 25 x 100 foot city lot was a more or less immediate consequence of the 1811 Commissioners Plan, which laid out a rectangular grid of avenues and cross streets over the whole of rural Manhattan north of the existing city as far up as 155th Street. Yet Commission Chief Surveyor John Randel’s map of the plan shows no subdivision of the plan’s roughly 1600 blocks into individual building lots, nor do the Commissioners themselves mention any further subdivision in their remarks to the plan. The eventual subdivision of Manhattan’s rural estates was left to the discretion of their owners, and necessarily so, as they alone had the legal right to subdivide — or not — however they pleased, if and when they decided to sell, which was usually after the opening — i.e., the acquisition by eminent domain — of new stretches of the Commissioners’ north-south avenues and the cross streets connecting them.

The Commissioners Plan did, however, impose some constraints on the subsequent sizes and shapes of city lots. The Plan’s rectangular blocks varied between 181 and 206 feet on their north-south axis but the average was almost exactly 200 feet. (They averaged 780 feet on their east-west axis but varied between 610 and 920 feet, with the result that only the 650 foot blocks between First and Second Avenues and the 800 foot blocks between Sixth and Twelfth Avenues were evenly divisible into 25 foot wide lots.) Because the 1811 Plan made no provision for mid-block alleyways, access to a property was only from the street, so that the simplest way to provide all the lots on a block with street access was to split the block lengthwise into two rows of lots — each row usually half a block or about 100 feet deep. In this respect the conventional wisdom is correct: in the area defined by the 1811 Plan, most lots ended up about 100 feet deep. More often than not, the subdivision of a block included avenue-fronting lots as well, often also 100 feet deep, but also often less — rarely more — than that, in order to make up the difference on the many blocks that were not evenly divisible into 25 foot wide lots.

The upper limit of six stories for most late 19th century New York buildings was due both to the physical constraints imposed by their “ordinary construction” — masonry, usually brick, exterior load-bearing walls and heavy timber joists supporting the interior floors — and to the fact that five flights of stairs was about the maximum the market would accept. Elevators, especially electric elevators, were installed only in the newer and taller buildings. Though the use of cast and wrought iron had begun in the 1830s, even the famous cast iron buildings of the 1850s were largely ordinary construction behind their elegantly sculptured fronts, and their height was subject to its same constraints. Iron and later steel frame construction only got underway in earnest in the 1870s and the results, however much they excited the imagination of the world, were statistically meager for many decades: the city’s 1912 buildings survey reported only 51 buildings above 20 stories, nine above 30 stories, three above 40 stories, and just one above 50 stories — out of a total of 92,749 on the island! Even in 1933 the average Manhattan building height was still only 5 3/4 stories: about 69 feet.

“Ordinary construction” constrained both the heights and the widths of buildings. Owing to the load-bearing capacity of brick, load-bearing walls would have to be at least 12 inches thick for a 50 foot high four story building. For a 60 foot high five story building the exterior walls would have to be 16 inches thick for the first story and 12 inches thick above that; for a 75 foot high six story building they would have to be 20 inches thick for the first story, 16 inches thick for the second, and 12 inches thick above that. Greater heights would require even greater thicknesses. In addition to the masonry itself, furring, laths, and plaster added as much as four inches to the thickness of exterior walls, so that a six story building might lose a full four feet of interior width on the first floor: a 16 foot wide building six stories high would then have a net first floor width of only 12 feet; a 20 foot wide building would net to 16 feet; and a 25 foot building to 21 feet. The upper floors fared better, of course, and row houses with party walls had the additional benefit that party walls — effectively braced by the structures to either side of them — needed to be no thicker than exterior walls, so that mid-row houses suffered only half the loss of interior width that a house standing alone would have lost.

Figure 2: 1887 diagram showing minimum exterior load-bearing masonry wall thicknesses for different residential building heights. From Laws Relating to Building in the City of New York, page 9.

Since the utility of a building derives from its interior, not its exterior dimensions, the thickness required for exterior load-bearing walls favored wider rather than narrower buildings. But owing to the load-bearing capacities of timber joists, ordinary construction also constrained maximum widths. Spans greater than about 25 feet — the building regulations of 1882 stipulated 26 feet — required additional mid-span support in the form of interior posts or load-bearing walls, the necessary thickness of which was in turn determined by both the building height and the total width to be spanned. As nearly all buildings on the island at the end of the 19th century were either wood frame (8 percent) or ordinary construction (90 percent) it is more than reasonable to infer that the typical exterior width of 20–25 feet was in large part determined by the material constraints of brick and timber construction, although exterior widths of as much as 28 feet 8 inches were possible without interior supports, and of course there were builders who exceeded this limit by as much as they felt they could get away with — enforcement of building codes has always been problematical — extending it to perhaps as much as 30 feet. Timbers were sold in lengths up to 40 feet, but the difficulty of transporting the longer lengths to a building site in the era of horse-drawn wagons, and of raising them into place with little if any power machinery, favored shorter lengths and therefore narrower buildings.

The depth of 19th century Manhattan buildings was not constrained by the materials and methods of construction but by the need to leave space at the back of the typical 100 foot deep lot for privies, stables, and perhaps miscellaneous storage, as well as for the sake of providing light and air to the rear of the buildings. Building depth was also determined by the uses and the budgets of the buyers: an 80 foot deep building was simply more expensive than one 50 or 60 feet deep, though for tenement buildings — defined as those housing three or more families — the deeper buildings allowed for higher occupancies and hence higher rents. Early tenements often put two buildings on a single lot: a larger one facing the street and a smaller one at the back of the lot, with the space for privies in between. That tenement depths did not, at least later in the century, exceed about 80 feet was due to health-related legislation requiring their builders to leave some 22 percent of the lot free, for the sake of sunlight and fresh air.

Virtually all buildings put up in the city in the 19th century directly abutted their neighbors to either side, although new tenement legislation eventually led to the “dumbbell” plan in which the middle of the building was narrower than the rest and equipped with windows so that light and air could reach rooms in the center of the building too. But this configuration did not affect the building lot itself, which remained a simple rectangle with the same width front to back.

Figure 3: a block with rows of “dumbbell” tenements still standing on the Lower East Side: the bounding streets are, clockwise from the top Suffolk, Rivington, Clinton, and DeLancey (map: City of New York Department of Information Technology and Telecommunications).

Building materials and methods, legislation, and even the Commissioners Plan all contributed to the typical size of a 19th century New York building, but they are not the whole story, nor do they answer the question of why there were so many buildings — or so few. Population growth and the distribution of effective demand — i.e., money, in the vernacular — across the population of buyers and renters also figure prominently. When the Commissioners filed their Plan in 1811, the city’s 99,000 people were housed in 11,000 or so residential buildings; at the same density, the 1,850,000 people living in Manhattan in 1900 would have required some 208,000 such buildings, whereas the actual number standing was about 82,300. This amounts to a more than 2.5-fold increase in the density of people per building, which was, by and large, accommodated by a comparable increase in the size of the average residential building, so that the volume of space available per person remained about the same, and buyer or even renter expectations were not compromised as the century wore on, at least at the upper end of the renter spectrum. The lower end of the spectrum, represented above all by the masses of immigrants who settled in the city year after year, got the worst of it, with interior volumes reaching the miserable lows of a few hundred cubic feet per person, as documented so movingly by Jacob Riis and other reformers. The net of all these factors in the largely unregulated world of 19th century New York real estate was a market equilibrium for buildings — in particular, for residential buildings — in the range of 20–25 feet wide, 60–80 feet deep, and four to six — but typically five — stories high, on lots that were typically 20–25 feet wide and 100 feet deep.

The frenzy of building in the 19th century not only transformed the surface of Manhattan as drastically as deforestation had transformed it in the 17th century, it also created a flourishing and even speculative market for real estate, something that could scarcely be said to have existed in 17th and 18th century New York. But where the deforested landscape of rural Manhattan had been a fertile ground for the growth of the real estate industry and its material product — buildings — in the 19th century, the built-up and subdivided urban island of 1900 was to prove a difficult platform from which to meet the changing conditions of the 20th century, which saw demand for buildings decline precipitously as the island’s population fell by 40 percent and its economy contracted during a long and painful transition from manufacturing to professional services. Vacant land was so scarce that despite the superior economics of the new large scale steel and concrete construction, the often painfully slow and almost always expensive process of acquiring enough contiguous lots to build profitably at the new scale slowed the replacement of the island’s aging building stock, though there were other retarding factors at work as well — e.g., the Great Depression, the Second World War, the complications of rent regulation. As a result, even today there are perhaps as many as 15–20 thousand “ordinary” buildings 20–25 feet wide, 60–80 feet deep, and four to six stories high still standing on the island of Manhattan, especially in the more heavily residential areas but even, if sparsely, in the areas downtown and midtown with the heaviest concentrations of high-rises. These by now antique survivors of a by-gone era are one of the principal sources of the island’s sense of human scale, and the sight of their modestly varying widths and heights, of their variegated brick and stone facades — some plainer, some highly ornamented — and even of the ironwork moiré of their street-fronting fire escapes, is one of the great pleasures of life in the city. The baleful 20th century consequences of their 19th century lot sizes for the construction of new housing in Manhattan, however, figure prominently among the reasons why Manhattan has become such a “luxury” city in the 21st century.

Figure 4: looking north at the mix of 19th and 20th century buildings in the blocks between between Amsterdam (Tenth) Avenue and Columbus (Ninth) Avenue, from 72nd Street to 75th Street (virtual image: Google Maps)

Richard Howe is a frequent contributor to the Blotter, and is writing a history of New York as a built environment. He also runs the photographic study New York in Plain Sight: The Manhattan Street Corners.


Sources and further reading
The progress of New York’s northward growth and concomitant subdivision in the 19th century and its can be followed on the land maps of the island beginning with Randel’s 1811 map for the Commissioners Plan, and moving on through Dripps’ maps of 1851–1852, the Perris’ maps of 1857–1859, and the Bromley atlases of 1879, 1891, and 1908, most of them available on-line at one or the other of the David Rumsey Map Collection, the Library of Congress, and the New York Public Library.

The Real Estate Record and Guide’s 1898 History of Real Estate, Building, and Architecture in New York City, drawn from this trade paper’s reporting over the years 1868–1898, compiled detailed statistics on building in the city as well as overviews of the leading real estate and construction firms; the complete Record and Guide is available on-line from Columbia University. The Union History Company’s long out of print History of Architecture and the Building Trades of Greater New York (1899) remains an astonishing source of data on just about every aspect of its subject, starting in the 17th century.

Whatever its flaws, the Rev. J. F. Richmond’s 1871 New York and its Institutions remains an invaluable source for the student of mid-19th century New York. D. T. Valentine’s Manuals of the Corporation of the City of New York 1841–1870 include numerous pre-Civil War building statistics. More data on the city’s buildings is reported in the New York State censuses of 1855, 1865, 1875, and 1895, in the U.S. Census reports on The Social Condition of Cities for 1880 and 1890, the 1900 Tenement Commission’s great report of 1903, and the city’s Heights of Buildings Commission report of 1913.

Christopher Gray’s Office of Metropolitan History website provides a marvelous on-line database of new building permits filed with the city between 1900 and 1986 and a useful guide to building research. The city’s own building records include extensive if incomplete data on building heights and ages.

Edward Allen’s professional handbook, Fundamentals of Building Construction Materials and Methods, is invaluable for its expositions of historical as well as contemporary materials and methods.