Side yard

A side yard is required open area running along a side lot line from the front yard (or street line) toward the rear of the lot. Side-yard requirements belong mostly to the lower-density residence districts, where they enforce the gaps that make housing detached or semi-detached; in rowhouse and apartment districts, buildings standing lot line to lot line are lawful, and side yards are generally not required at all.

The rules can govern even optional open strips: where a side yard is provided on a lot that does not require one, minimum-width provisions may still apply, because a too-narrow gap traps debris and light poorly — worse than no gap. As with all yards, permitted obstructions are enumerated and district-specific.