What alterations are being filed in New York City?

105,367 alteration filings are on record — 92.9% of every filing published here, and the largest single class of work in it.

An alteration covers everything from a new storey to a partition wall, so the count says how much work is filed, not how much of the city is changing shape. The catalog is a rolling window over recent Department of Buildings activity rather than the city’s whole history, which is why the figures above are given as shares — a share survives the window, a count does not. How the record is built.