In the CBC District, the size, location and screening of such parking spaces shall be approved by the Planning Board during the permitting process, giving due consideration to the neighborhood characteristic, emphasizing the need to concentrate parking in as unobtrusive a location on the side and rear of the property as possible. Surfacing of the drives and parking areas shall be all-weather surface. The parking area in a given property shall not exceed 50% of the area of the property not covered by buildings.