Loading space. In new construction only, structures used for manufacturing, storage, warehousing, laundry, dry cleaning or other uses which receive or distribute materials or merchandise by vehicles shall have adequate space on the premises for standing, loading and unloading to avoid undue interference with public use of streets. This space, unless otherwise adequately provided for, shall include a ten-foot-by-twenty-six-foot loading space, with fourteen-foot height clearance, for every 20,000 square feet of building floor used for these purposes.