Minimum buffer area. Any lot containing a professional office as a principal use shall be required to provide a landscaped buffer area along any lot line that abuts a property used for a residence. The buffer area shall be at least 10 feet in depth, measured perpendicular to the lot line. No building, parking area or other paved area shall be permitted to encroach into the required buffer area. The developer shall provide landscaping, fencing, or walls in the buffer area sufficient to screen the lot containing the professional office from the view of the lot containing the residence.