Several specific consequences flow from the Substandard Hillside Limited Street designation. Maximum grading is reduced to seventy-five percent of the by-right limit. The minimum front yard setback can drop to five feet. Maximum height within twenty feet of the front lot line is constrained to twenty-four feet measured from the centerline of the street. Open unenclosed stairways, porches, platforms, and landings cannot project into the front yard.

A fire sprinkler system is required on any lot fronting a Substandard Hillside Limited Street, regardless of the lot’s distance from a fire station. The same requirement applies to lots more than two miles from a Truck Company station or more than one and a half miles from an Engine Company station, but the substandard street designation is its own independent trigger.

Practitioner takeaway: confirm the street classification with the Bureau of Engineering before committing to a design. A property whose street turns out to be Substandard Hillside Limited can require a discretionary approval that adds months to the timeline. Owners who hear that early can decide whether to pursue the project as-of-right with a smaller scope, or commit to the discretionary path.