Retail tenants include Bar Vida, Jade Nail & Spa, Darien Barber Shop and Check Body-Mind.
Saugatuck Commercial Real Estate (SCRE) was the exclusive broker of the transaction.
The company will be opening in July at the former Garelick & Herbs space in Westport’s Saugatuck Center at 580 Riverside Ave.
Aubuchon, which plans to move into the Bart Center in the late fourth quarter, is replacing Stepney Hardware, which closed in January after 60 years.
The building at 1010 Summer St. is about 70 percent occupied; USA Equity Trust will temporarily have offices on the third floor.