4 LEFT SIDE IMAGES: ROOF GENEOLOGY
(Left side, top image, building ages of Financial District reflecting which era they were built in: Pre 1916, 1916-1961, Post 1961) New York City’s roof heights have been shaped by building codes, driven by the desire to prevent skyscrapers from eliminating daylight from the streets. In 1916, the setback codes came into play, and building tops began to be terraced (“wedding cakes”) to permit more light down into the street canyons. The 1961 code change allowed for buildings to be built straight up without setbacks which was more structurally efficient, but required the buildings to give back to the street with more public plazas, which allowed space and light.
(Left side, 2nd image down) A 3-D diagram showing the difference between 1916 and 1961 buildings, with and without setbacks.
(Left side, 3rd image down) The Financial District from above.
(Left side, 4th image down) The darkest black of the previous image extracted reveals the figure-ground shape of the street canyons in the Financial District. The narrowness of the Financial District’s old streets coupled with its extra tall buildings caused by the economic history there causes this acute darkness.
4 RIGHT SIDE IMAGES: REGIONAL GENEOLOGY:
(Right side, top image): New York’s topography as seen in grayscale spectrum. The whitest areas are the highest.
(Right side, 2nd image down): Upping the contrast of the previous image shows only the highest areas. We can explain these areas based on significant geological events. From left to right: the line of the Catskill Mountains dating back 200 million years, the line of the Terminal Morraine on Long Island dating back 18,000 years, and the Hudson River low point. The Ice Ages were a “re-zoning” of New York’s height just as the setback laws were a “re-zoning” of New York City skyscrapers’ heights.
(Right side, 3rd image down): Civilized areas in red, showing how colonization has occurred at the lowest points of topography, along rivers and bodies of water. Topographic height therefore is a repellent to civilization. The same can be said for rooftops in the Financial District as they have more intense conditions of light and wind.
(Right side, 4th image down): Highest points inverted to black.