(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-17" Residential Districts, subject to all qualifications imposed on such uses;

(b) Attached single-family and duplex dwellings in groups of not more than 10; provided, that each single-family attached dwelling shall not be less than 18 feet in width, and each duplex attached dwelling shall not be less than 24 feet in width.

(2) Area Regulations.

(a) General Provision. Irrespective of the size of the property concerned, every principal building and/or use thereon shall have its lot lines indicated, and all buildings thereon shall be erected, constructed, altered or used in accordance with the area provisions herein contained as applied to the lot so indicated.

(b) Lot Width and Area.

(.1) Single-family dwellings: The minimum lot width shall be 18 feet, and the minimum lot area shall be 1,620 square feet.

(.2) Duplex dwellings: The minimum lot width shall be 24 feet, and the minimum lot area shall be 2,160 square feet.

(.3) Multiple dwellings: The minimum lot width shall be 35 feet, and the minimum lot area shall be 1,050 square feet for each family contained therein.

(.4) Buildings other than dwellings: The minimum lot width shall be 42 feet, and the minimum lot area shall be 3,780 square feet.

(c) Occupied Area.

(.1) Single-family dwellings: No more than 50% of the area of the lot shall be occupied by buildings.

(.2) Duplex dwellings: Not more than 40% of the area of the lot shall be occupied by buildings.

(.3) Multiple dwellings and buildings other than dwellings: Not more than 35% of the area of the lot shall be occupied by buildings.

(d) Building Set-back Line. The building set-back line shall be 15 feet back from all street lines.

(e) Yards.

(.1) Front. The minimum depth of a front yard shall be the depth required between a street line and the building set-back line, as herein specified.

(.2) Side. When side yards are used, they shall have the following minimum widths:

(.a) Detached single-family and duplex dwellings: 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 lot 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;

(.b) Semi-detached single-family and duplex dwellings: Every semi-detached single-family dwelling and every semi-detached duplex dwelling shall have a side yard not less than eight feet wide; provided, that such a dwelling located on a corner lot shall have the building set-back on the intersecting street adjudged a side yard (which shall be not less than the set-back required);

(.c) Detached and semi-detached multiple dwellings: Every multiple dwelling shall have at least one side yard, the minimum width of any side yard shall be not less than 12 feet; provided, that every such dwelling located on a corner lot shall have the building set-back on the intersecting street adjudged a side yard (which shall be not less than the set-back required), and the other or inside yard may be reduced to a width of not less than eight feet;

(.d) Attached dwellings at end of permissible group: Every attached dwelling which is the end unit of a permissible group shall have a side yard with a minimum average width of 12 feet; provided, however, that no portion of said yard shall be less than eight feet in width; and provided further, that such a dwelling located on a corner lot shall have the building set-back on the intersecting street adjudged a side yard (which shall not be less than the set-back required);

(.e) Buildings other than dwellings: Every building other than a dwelling shall have two side yards neither of which shall be less than 12 feet wide.

(.3) Rear.

(.a) Single-family dwellings and duplex dwellings shall have a rear yard of not less than 20 feet;

(.b) Multiple dwellings and buildings other than dwellings shall have a rear yard of not less than 25 feet.

(.4) Courts.

(.a) Open courts not between the wings of the same building, when used, shall have a minimum width not less than the required minimum width of a side yard;

(.b) Inner courts and open courts between the wings of the same building, when used, shall be governed by the provisions of § 14-231(1) of this Title.

(3) Height Regulations.

(a) The maximum height of a dwelling shall be 35 feet above the average ground level at the base of building, but in no case over three stories.

(b) The permitted height of non-residential building shall be 35 feet, except that one foot of additional height may be added for each additional foot the building sets back from all lot lines; provided, however, that the maximum height of any such building shall be 60 feet (subject to the provisions of § 14-231(2)).

(4) Application to Existing Dwellings. Any dwelling in this district may be converted to contain a greater number of families under the following provisions:

(a) If said dwelling, as converted, will meet the Use, Area and Height Regulations as set forth above; or,

(b) If, in lieu of meeting the Use, Area and Height Regulations as set forth above, the following provisions are complied with:

(.1) For the number of families to be increased, the majority of the floors of the dwelling must have an area of at least 700 square feet per floor and the total floor area must be a minimum of 1,600 square feet. In such a case, additional families may be added as follows:

(.2) In addition, families shall not be added unless there is provided at least 800 square feet of yard space (including any area used for parking), for each family contained in the building.

(c) Any construction or alteration made in connection with any conversion permitted in this paragraph shall conform to the area and height regulations of this district; provided, that where necessary, legally required fire escapes may exceed such regulations.

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