GreenOak Real Estate has closed on the disposition of a mixed-use building in Soho for $21 million to a joint venture of Churchill Real Estate Holdings and Square Advisors. The 21,500 square foot building, located at 5-7 Mercer Street, contains nine rental residential units and the a Oak + Fort clothing store and Billionaire Boys Club, the clothing line of Pharrell Williams. The seller bought the asset for $16.5 million in 2013.