For developments or enlargements, there shall be a strip of continuous planting at grade of not less than three feet in width along the entire front wall of such development or such building that is enlarged. In the event a building is constructed within three feet of the street line, the owner of the building shall apply to the Bureau of Highway Operations for permission to locate a portion of such planting strips on a public sidewalk within the street line. A copy of such application shall be submitted with the new building application when filed at the Department of Buildings. Such sidewalk planting requirement may be waived by the Department of Buildings only upon receipt of written disapproval by the Department of Transportation.