(1) Use Regulations. The specific uses permitted in this district shall be the erection, construction, alteration, or use of buildings and/or land for:

(a) The uses permitted in "R-10" Residential Districts, except attached buildings; provided, that uses permitted shall be subject to all qualifications imposed on such uses in the "R-10" Residential District.

(b) Signs as permitted in "R-2" Residential Districts.

(2) Area Regulations.

(a) Lot Width and Area. The minimum lot width shall be 50 feet, and the minimum lot area shall be 10,000 square feet.

(b) Occupied Area. Not more than 50% of the lot area shall be occupied by buildings.

(c) Open Area. The open area shall be not less than 50% of the lot area and shall consist of front, side and rear yards of at least the minimum dimensions herein designated.

(d) Building Set-back Line. The building set-back line shall be 20 feet back from all street lines.

(e) Yards, General Provisions. Subject to the minimum yards set forth in paragraphs (d), (f), (g) and (h), the front, side and rear yards in this district shall be defined as the open area created on the lot by the following requirements:

(.1) Any wall of a structure containing one or more legally required windows shall be located so that every point of said wall shall be a minimum horizontal distance from the lot line equal to one-half the height of said point above the average ground level at the base of the structure; provided, that where said wall faces upon a street, said distance may be measured from the centerline of said street rather than the lot line.

(f) Front Yards. The minimum depth of a front yard shall be the depth required between the street line and the building set-back line, as herein specified, except where a greater front yard is required by paragraph (e) above.

(g) Side Yards. Except where a greater width is required by paragraph (e) above, side yards shall be required as follows:

(.1) Every detached single-family dwelling and every detached duplex dwelling shall have two side yards, neither of which shall be less than eight feet wide; provided, that every such dwelling located on a corner shall have the building set-back on the intersecting street adjudged a side yard (which shall not be less than the set-back required), and the other or inside yard shall be not less than six feet wide (subject to exception for existing buildings, see § 14-104(12)).

(.2) Every semi-detached single-family dwelling and every semi-detached duplex dwelling shall have a side yard not less than 10 feet wide; provided, that such a dwelling located on a corner shall have the building set-back on the intersecting street adjudged a side yard, and its width shall not be less than set-back required.

(.3) Every detached multiple dwelling and every building other than a dwelling shall have two side yards, neither of which shall be less than eight feet wide; provided, that every such dwelling or building located on a corner shall have the building set-back on the intersecting street adjudged a side yard which shall not be less than the set-back required (subject to exception for existing buildings, see § 14-104(12)).

(.4) Every semi-detached multiple dwelling shall have a side yard not less than 16 feet wide; provided, that every such dwelling located on a corner shall have the building set-back of the intersecting street adjudged a side yard and its width shall not be less than the set-back required (subject to exception for existing buildings, see § 14-104(12)).

(h) Courts. Courts, when used, shall be in addition to the open area required, and shall have minimum widths as follows:

(.1) The minimum width of open courts not between wings of the same building shall be the same as for side yards;

(.2) The minimum width of courts between wings of the same structure shall be determined by the following requirements:

(.a) For buildings of three stories or less and not in excess of thirty-five feet high, the minimum width shall be not less than the length or depth of such court.

(.b) For buildings over three stories or over thirty-five feet in height, whichever is less, the minimum width shall be not less than the length or depth of such court plus one-third of that portion of the height of the building over three stories or thirty-five feet.

(.3) The dimensions of an inner court shall be equal to the height of the higher wall between which each dimension of the inner court is being measured.

(i) Rear Yards. Except where a greater depth is required by paragraph (e) above, the minimum depth of a rear yard shall be 20 feet.

(3) Height Regulations. There shall be no height regulations except as height may be limited by the other applicable provisions of this district.

(4) Floor Area. No building in this district shall have a gross floor area (as defined in § 14-102(25)) greater than that permitted under the provisions herein set forth:

(a) Basic Floor Area. Every building in this district shall be permitted a gross floor area equal to 150% of the area of the lot.

(b) Additional Floor Area. In addition to the Basic Floor Area, any building in this district shall be permitted additional gross floor area in accordance with the following provisions, which shall be cumulative in their effect:

(.1) Buildings Constructed Back from Streets Fifty Feet or More in Width: Where a building or any portion thereof is constructed back at ground level, from the street line of any street of 50 feet or more in width, there shall be permitted 2 square feet of additional gross floor area for each square foot between the street line and the building (including areas of required yards); provided, that the foregoing shall not apply to any area which lies further from the street line than 50% of the depth of the lot;

(.2) Buildings Constructed Back from Streets Less than Fifty Feet in Width: Where a building or any portion thereof is constructed back, at ground level, from the street line of any street of less than 50 feet in width, there shall be permitted 1 square foot of additional gross floor area for each square foot between the street line and the building (including areas of required yards); provided, that the foregoing shall not apply to any area which lies further from the street line than 50% of the depth of the lot;

(.3) Buildings Constructed Away from Rear Lot Line, Not a Street Line: Where a building or any portion thereof is constructed away, at ground level, from a rear lot line which is not a street line, there shall be permitted 0.7 square feet of additional gross floor area for each square foot between the rear lot and the building (including areas of required yards); provided, that the foregoing shall not apply to any area which lies further from the rear lot line than 50% of the depth of the lot;

(.4) Buildings Constructed With Open Arcades: Where a building or any portion thereof is constructed so that at the ground level there is an open arcade of at least 10 feet in unobstructed width which abuts a sidewalk and is open to public use at all times, there shall be permitted 0.3 square feet of additional gross floor area for each square foot in said arcade; provided, that this subparagraph shall also apply to buildings cantilevered to produce an effect similar to an arcade at least 10 feet in unobstructed width;

(.5) Open Areas Separated from a Street Line by an Open Arcade: Where a building or any portion thereof is constructed back, at ground level, to create a continuous open area which is separated from the street line only by an open arcade, there shall be permitted 2 square feet of additional gross floor area for each square foot of such open area where said street line is of a street which is 50 feet or more in width, or 1 square foot of additional gross floor area for each square foot of such open area where said street line is of a street which is less than 50 feet in width, subject to the following provisions:

(.a) The foregoing shall not apply to any area which lies further from the street line than 50% of the depth of the lot;

(.b) "Continuous open area" as used in this subparagraph, shall mean an open area which is unobstructed (except for passage through the open arcade) in a straight line from the building to the street line;

(.c) The additional gross floor area permitted for the area within said open arcade itself shall in all cases be governed by subparagraph (.4) above;

(.6) Other Open Areas Provided at Ground Level: Where a building or any portion thereof is constructed so as to provide open areas at ground level other than those described in subparagraphs (.1) through (.5) above, there shall be permitted 0.6 square feet of additional gross floor area for each square foot of said open area;

(.7) Buildings Constructed Away from any Lot Line at First or Second Story Roof Level: Where a building or any portion thereof is constructed away from any lot line (whether or not said lot line is also a street line) above ground level but not beyond the second story roof level, there shall be permitted 0.5 square feet of additional gross floor area for each square foot between the lot line and the building; provided, that where a building or any portion thereof is constructed away from a lot line at successive distances at different levels, the computation of permitted additional gross floor area shall be made for each level, beginning at the ground level, and not including, in each case, areas between the building and the lot line which have already been used in computing permitted additional gross floor area at another level;

(.8) Areas Used or Intended to be Used for Parking: Any area used or intended to be used for parking purposes shall not be included as permitting additional gross floor area under the provisions of subparagraphs (.4) and (.5) above.

(5) Off-street Parking. See § 14-1400 of this Title.