A professional building exceeding 4,500 square feet of gross floor area. Lot frontage shall be equal to at least 1/2 the average depth of the lot, but not less than 150 feet. Sufficient parking spaces shall be provided to accommodate all persons reasonably expected to patronize said professional building at one time, which shall not be more than twice the number of spaces required under 7.05H. The requirements of 7.09 hereof shall otherwise be met except the Commission may require wider buffers, wider side or rear yards and a deeper building setback than are otherwise required where needed to screen adequately adjacent residential zones, or to meet the standards set forth in 8.04, provided that the structural coverage including parking and loading area is not required to be reduced to less than 60% of the lot area. The wall of the office building facing the street shall not be longer than 200 feet or twice the distance which it is set back from the street line, whichever is greater. All portions of the lot in excess of 10 acres are excluded in determining maximum structural coverage permitted.