(a)        In all districts, the Board of Standards and Appeals may modify use and bulk regulations to permit the enlargement or extension of floor area of a conforming or non-conforming use listed in Section 15-60 (REFERENCED COMMERCIAL AND MANUFACTURING USES), provided that:

(1)        such use is not subject to termination pursuant to Section 52-70, et seq.;

(2)        the use for which such special permit is being sought has been lawfully located on the zoning lot on which the expansion is to occur, or a portion thereof, for five years or more;

(3)        the building in which such use is located has not previously been enlarged, pursuant to Sections 11-412, 43-121 or 72-21;

(4)        the use is not listed in Use Group 18; and

(5)        in a Residence District, such enlargement or extension shall be permitted in existing floor area or on a vacant portion of a zoning lot only when no lawful residential use has occupied such floor area or vacant portion of a zoning lot at any time during the five years prior to the date of application for such special permit.

(b)        Any enlargement or extension permitted pursuant to this Section shall be subject to the following requirements:

(1)        the permitted enlargement or extension may be the greater of:

(i)        45 percent of the floor area occupied by such use on December 17, 1987; or

(ii)        2,500 square feet additional to the floor area occupied by such use on December 17, 1987.

In no event shall the amount of enlargement or extension under paragraph (b)(i) of this Section exceed 10,000 square feet additional to the floor area occupied by such use on December 17, 1987;

(2)        unless the zoning lot is located within an M2 or M3 District, more than 300 feet from a Residence District boundary, any enlarged or extended portion, or activity generated by such enlargement or extension, including storage and processing, shall be in completely enclosed buildings;

(3)        in the case of a non-conforming use, such enlarged or extended use shall conform to all performance standards applicable in an M1 District located at the boundary with a Residence District; however, conforming uses shall conform to the applicable performance standards of the district in which they are located;

(4)        no open uses of any kind, including storage or processing, shall be permitted within 30 feet of a rear lot line that is located within a Residence District or within 30 feet of the rear lot line that coincides with a rear lot line of a zoning lot in a Residence District;

(5)        no enlargement or extension that exceeds 16 feet above curb level shall be permitted within 30 feet of the rear lot line that coincides with a rear lot line of a zoning lot in a Residence District;

(6)        no enlargement or extension that exceeds 16 feet above curb level shall be permitted within eight feet of the side lot line that coincides with a rear lot line of a zoning lot in a Residence District;

(7)        no open uses of any kind, including storage or processing, shall be permitted within eight feet of the side lot line that coincides with a rear lot line of a zoning lot in a Residence District;

(8)        no enlargement or extension, or open uses of any kind, including storage or processing, shall be permitted within eight feet of the lot line which coincides with a side lot line of a zoning lot in an R1, R2, R3, R4 or R5 District; and

(9)        no side yard shall be required in an R6, R7, R8, R9 or R10 District or in a Commercial District or Manufacturing District; however, if such side yard is provided, it must be at least eight feet in width.

(c)        In granting such special permit, the Board shall find:

(1)        that such enlargement or extension will not generate significant increases in vehicular or pedestrian traffic nor cause congestion in the surrounding area;

(2)        that there will be adequate parking for any vehicles generated by such enlargement or extension;

(3)        that any required side yard shall be suitably landscaped or fenced as the Board shall prescribe;

(4)        that any accessory parking or loading generated by such enlargement or extension shall be suitably buffered from adjacent uses by methods that the Board shall prescribe; and

(5)        that the special permit, if granted, will not alter the essential character of the neighborhood or district in which the use is located, nor impair the future use or development of the surrounding area.

The Board may prescribe appropriate conditions and safeguards including, if appropriate, limitations on hours of parking and delivery, requirements for off-street loading, and location of curb cuts to minimize adverse effects of the enlargement, extension or existing uses on the character of the surrounding area, and to protect residential or commercial zoning lots.