The whiner’s house is forth to left from the old brick apt. building in photo above.
http://www.nyc.gov/html/dcp/html/zone/zh_resdistricts.shtml ~ read this. About halfway through you find out about CONTEXTUAL ZONING and this new building is zoned R7, and it’s butt up against an R5 ~ which is low rise ~ R5 doesn’t have a 3 foot setback ~ if any at all. Looks like zero lot line construction is allowed ~ however, R7 of any kind is prohibited in this context where there are low rise dwellings in the immediate vicinity. They have some other detailed standards, but if some minor eyeballing calls into question the context it’s probably pretty much the case somebody violated some serious stuff with the new building. Those standards are most likely overriden by an agreement to reserve one condo or apartment inside the new building for low income people on Section 8. This piece doesn’t address those cases but this is New York City and the totalitarian left runs everything so the guys on welfare have rights that are greater than those of the mere property owners next door.