Witnick Real Estate Partners purchased a mixed-use, multifamily apartment building in Union Square for $23 million. The building, located at 30 East 14th Street between Fifth Avenue and University Place, came with 30,720 square feet of air rights and sold for approximately $1,124 per square foot, meaning that a larger building might be on the way. But, plans for the property are unclear and Witnick did not respond to a request for comment.