The East Cooper side of Charleston Harbor will soon see the development of an 18-acre parcel that will furnish 1 million square feet of office space, retail, hospitality, and residential space.  Bennet Hospitality of Charleston and Atlanta-based Holder Properties are the developers of the Ferry Wharf project.  The development is already under construction with a five-story 120,000 square foot office building called Portside. Serendipity Labs of New York preleased 30,000 square feet, and financial firm Merrill Lynch 25,000 square feet…