Another view of lower Manhattan, again from a slightly odd angle. We’re looking north from the west side of the very southern tip of the island – most likely from the roof of the Whitehall Building. The Library of Congress says 1900 to 1915, but the Woolworth Building and Equitable Buildings are complete, so circa 1915 is probably more accurate.
This is essentially the same view that I discussed recently, but maybe two years later. In the older photo, there’s a vacant lot with construction where the Adams Express Building would be; in the photo above, Adams Express is the most prominent building in view, with 32 stories of regularly-spaced identical windows in its white-brick facades and a somewhat incongruous cornice. Just north of Adams Express is the American Railway Express Company Building, another delivery company, and then north of that is the Empire Building. In the older photo, we were looking at the back of the Empire Building because the site of the Railway Express building was still an old seven-story building.
There’s a certain grouping of the visible buildings. We have the three spires, including the tallest and third buildings in the world: Woolworth on the left, Singer with its curved mansard in the middle, and the stepped pyramid of Bankers Trust on the right. We have two very tall flat-tops: Adams Express and (immediately behind Adams and just visible over its top) the new Equitable Building. And then we have a bunch of 21 to 23 story flat-tops: Empire, Railway Express, the Trinity Building (just to the left of Empire, on the far side of the Trinity Church graveyard), Two Rector Street (just to the left of the Trinity Building), the Hudson Terminal Buildings (to the left of Two Rector), Columbia Trust (just to the right of Adams), and the slightly shorter (14 stories) Hamburg-American Steamship Company (at the lower right corner). All of those buildings were constructed before New York had any kind of zoning restrictions on tall buildings, and the city has never had a cap on height. So why so many similar-size towers? There are two answers, which say much the same thing but in two very different ways.
The formal answer is the idea of economic height. Based on the cost of land, the expected rent per square foot, the amount of incremental additional square feet you get by adding more floors, and the cost of maintenance, you can calculate the height that maximizes income. As your building gets taller, you have to add more elevators, which means you don’t get as much additional floor area as you might think, and your maintenance costs increase as well. For a given lot size; given land, construction, maintenance costs; and the standard architectural layout of the era, calculating the economic height is fairly straightforward. The prevalence of buildings a bit over 20 stories in 1915 suggests that the developers of the era believed that to be the economic height. If you have a bigger lot, as Woolworth and Adams do, for example, it can make sense to go taller.
The less formal, slightly odder answer is to extend the idea of vernacular architecture to skyscrapers. My mental image of vernacular is that it’s what people build when they simply want a building and aren’t thinking (or being told) about design. How does that apply to skyscraper, which are heavily-designed structures? Frank Woolworth wanted to maximize his income and make an architectural statement on his prominent site; while the Railway Express Company was looking for rental income on an ordinary lot and ended up with a generic (for the time) building. In the end, the skyscraper vernacular is the economic height with as few frills as possible.
More on the topic here: The Structure of Skyscrapers