NYC Zoning Handbook: Appendix E
Residence Districts: Yard Requirements for Residential Buildings
 On corner lots, one front yard may have a lesser depth: 15 feet in
R1-2, 10 feet in R3, R4 or R5 districts.
 Rear yards are not required for corner lots.
 A residential building may extend 10 feet into a required rear yard
to a height no greater than 21 feet.
 A minimum width of 8 feet is required between a new building and a
building on an adjacent zoning lot. A minimum width of 10 feet is
required if an adjacent zoning lot contains a detached building with
side yards totaling 13 feet with one yard at least 5 feet wide or a
semi-detached building with a side yard at least 8 feet wide.
 If both adjacent buildings are set back further than 10 feet, the
front yard must be at least as deep as one of the adjacent front yards
although it need not exceed 20 feet.
 If both adjacent buildings are set back further than 5 feet, the
front yard must be no deeper than the deepest adjacent front yard and no
shallower than the shallowest adjacent front yard, although the front
yard depth need not exceed 20 feet.
 A front yard depth of 10 feet only is also allowed. Front yard
depths of between 10 and 18 feet are not permitted. The minimum front
yard depth for R4 infill and R5 infill is 18 feet.
 In R3-1, R3-2, R4, R4-1, R4B and R5 districts, where buildings share
or abut walls along common side lot lines, side yards are not required.
 In R6 through R10 districts, yard requirements for residential
buildings in contextual districts are the same as those in the
corresponding residential district without a letter suffix. For
residential buildings in R6, R6B, R7 and R7B districts developed under
the Quality Housing Program, the front yard requirement is 5 feet (on
narrow streets only).