The Hendersonville City Council placed the final piece of the puzzle Thursday to redevelop the historic Grey Hosiery Mill into a boutique hotel. During their Thursday night meeting, council members approved the agreement between the city and developer Belmont Sayre LCC (Grey Mill Ventures LCC ). The developer plans to renovate the historic mill into a 57-room, one-story boutique hotel complete with a 2,000-square-foot event space. The lengthy document governs the redevelopment of the property over the next 20 years. Any amendments to the agreement must go through a formal public hearing process before City Council. The agreement contains language requiring the developer to place historical photos of the mills as well as text describing its history in a place that’s convenient and accessible to the public. The city has also committed to street scape improvements along Fourth Avenue to better connect the hotel to Main Street.