Lay the whole island out in a single rectangular grid regardless of the ground: avenues 100 ft wide running its length, cross streets 60 ft wide across it, and blocks 200 ft deep between them, the houses to be straight-sided and right-angled because such houses are cheapest to build and most convenient to live in.
avenue 100 ft (30 m) · street 60 ft (18 m) · block 200 ft (61 m) deep, 600–900 ft long
The grid runs with the island, about 29° east of true north, and every cross street is exactly as wide as every other except a handful of 100-foot crosstown streets. The lots it made (25 by 100 feet for a row house, whole blockfronts for the later towers) were the units that the 1916 zoning law and every skyscraper of the 1920s had to work within.
At the street line a building may rise to a multiple of the street’s width; above that it must stay behind a plane drawn from the centre of the street, stepping back as it rises.
street wall H₀ = k × street width (k = 1 … 2½) · above it, 1 m back for every 2k m up
Over one quarter of the lot area, a tower may rise to any height, free of the setback planes.
tower footprint ≤ 25% of lot area · height unlimited
Divide the city into residence, business and unrestricted districts, and admit to each only the uses that belong there, so that lofts and factories cannot invade the shopping streets and houses.
Treat the largest mass the zoning law allows as a block to be sculpted: cut it into setbacks that give usable, well-lit floors, and gather the remaining height into a tower that ends in a crown.
Cap the height of new buildings (at 130 feet from 1893) so that the business district does not become a canyon of towers; the cap was raised to 260 feet in 1902 and lowered to 200 in 1911.
1893: 130 ft (≈ 40 m) · 1902: 260 ft · 1911: 200 ft
Treat the city’s railways, elevated lines and streetcars as a single system serving the business centre, and plan their stations and routes together, relieving the elevated loop with subways and through routes.
Cite this page Chris Paton, “One grid for the whole island”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/manhattan-grid-1811. Text, drawings and models licensed under CC BY-NC 4.0.