Six Sigma NYC, a boutique design and development firm, has plans to create a new luxury condo building in Chelsea. The site, currently a Tuck-It-Away Self-Storage facility at 517-523 W. 29th St., was acquired for $54.75 million from Nick Sprayregen, the president of Tuck-It-Away, which has more than a dozen sites in New York City and the metro area.

Six Sigma president Jason Lee and partner Johnny Wan played an integral role in negotiations with Stephen Ferrara of Town Residential, who assisted the seller on the deal.