(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-3" Residential Districts, subject to all qualifications imposed on such uses;

(b) Detached and semi-detached duplex dwellings;

(c) Detached and semi-detached multiple dwellings.

(2) Area Regulations.

(a) General Provisions. Irrespective of the size of the property concerned, every principal building and/or use thereon shall have its lot lines indicated, and all buildings 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 35 feet, and the minimum lot area shall be 3,150 square feet;

(.2) Duplex dwellings and buildings other than dwellings: The minimum lot width shall be 50 feet, and the minimum lot area shall be 5,500 square feet;

(.3) Multiple dwellings: The minimum lot area shall be 2,700 square feet for each family contained therein and the minimum lot width shall be 60 feet;

(c) Occupied Area. Not more than 40% of the lot area shall be occupied by buildings.

(d) Open Area. The open area shall be not less than 60% of the lot area and shall consist of front, side, and rear yards of at least the minimum dimensions designated.

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

(f) Yards.

(.1) Front. 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.

(.2) Side.

(.a) Detached single-family dwellings: Each detached single-family dwelling shall have two side yards, each of which shall not 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 may be reduced to a width of not less than six feet;

(.b) Detached duplex dwellings: Each detached duplex dwelling shall have two side yards, the aggregate width of which shall be not less than 25 feet, and neither of which shall be less than 10 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 side yard may be reduced to a width of not less than seven feet;

(.c) Detached multiple dwellings: Each detached multiple dwelling shall have two side yards, each of which shall not be less than 15 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 side yard may be reduced to a width of not less than 12 feet;

(.d) Semi-detached single-family dwellings: Each semi-detached single-family dwelling shall have one side yard, which shall not be less than 16 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);

(.e) Semi-detached duplex dwellings: Each semi-detached duplex dwelling shall have one side yard, which shall not be less than 20 feet wide;

(.f) Semi-detached multiple dwellings: Each semi-detached multiple dwelling shall have one side yard, which shall not be less than 25 feet wide;

(.g) Buildings other than dwellings: Every building other than a dwelling shall have two side yards neither of which shall be less than 15 feet wide; provided, that every such building located on a corner lot shall have the building set-back adjudged a side yard which shall not be less than the set- back required.

(.3) Rear.

(.a) Single-family and duplex dwellings: The minimum depth of a rear yard shall be 20 feet.

(.b) Multiple dwellings and buildings other than dwellings: The minimum depth of a rear yard shall be 30 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 the building, but in no case over three stories.

(b) The permitted height of non-residential buildings 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 (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 a least 700 sq. ft. per floor and the total floor area must be a minimum of 2,000 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 2,500 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 when necessary, legally required fire escapes may exceed such regulations.

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