Design Requirements for Single- and Two-family Residences
R1 R2 R3 R4 R5 R6
In R1, R2, R3, R4 and R5 Districts, for single- and two-family residences that have a street wall within 50 feet of the street line, and in R6 Districts, for detached and semi-detached
single- and two-family residences that have a street wall within 50 feet of the street line, where the level of the lowest occupiable floor is five feet or more above curb level, at least one of the following visual mitigation elements shall be provided. For such residences where the level of the lowest occupiable floor is nine feet or more above curb level, at least two of the following visual mitigation elements shall be provided.
Where provided as a mitigating element, a porch shall have a finished floor at least six inches below the lowest occupiable floor and have a width at least 70 percent of the aggregate width of all street walls within 25 feet of the street line. The depth of the porch must be at least five feet, and the porch may not be closer to the street line than five feet. Open porches shall count as one mitigating element and roofed porches shall count as two mitigating elements, provided that for such roofed porches, all structural elements shall have a minimum width or depth of at least three inches, and such roof shall have a depth of at least five feet measured perpendicular to the street wall and extend along at least 70 percent of the width of the street wall. A balcony directly above a porch and a trellis or arbor with structural members spaced no further than 30 inches on center that cover such porch may be considered a porch roof for the purposes of this Section.
(b) Stair direction change
Where provided as a mitigating element, stairs shall be constructed between grade and the lowest occupiable floor or porch, as applicable, which shall change direction at least 90 degrees in plan at a point no lower or higher than two feet from the beginning and end of the stair run.
(c) Raised front yard
Where provided as a mitigating element, the grade between the street line and street walls within 25 feet of the street line, and their prolongations, shall be elevated above curb level so that a line drawn midway between the street line and such street walls and prolongations is at least 18 inches above curb level at all points, except for pedestrian ways, vehicular access and off-street parking spaces permitted pursuant to Section 64-50 (SPECIAL PARKING REGULATIONS). The area with final grade above curb level must be greater than 50 percent of the total area between the street line and street walls within 25 feet of the street line and their prolongations. Such raised yards shall be planted to comply with Section 23-451.
(d) Trees or shrubs at least three feet high
Where provided as a mitigating element, trees or shrubs that attain a height of at least three feet shall be provided between the street line and street walls within 25 feet of the street line and their prolongations. Planting beds shall be at least three feet wide in plan, measured parallel and perpendicular to the street line. The length of each planted area shall be measured by inscribing each planted area within a rectangle and measuring the longest dimension of such rectangle. The total length of planted areas shall be greater than 60 percent of the lot width, and be planted to screen at least 50 percent of the length of the street wall.
However, no mitigation shall be required where more than 50 percent of the street wall of a building is within three feet of the street line.