Guests joined the Chicago Architecture Foundation at the Builders BLDG on October 12 for drinks and hors d’oeuvres to celebrate Open House Chicago, CAF’s free architecture festival. Until recently, the Builders BLDG was one of the city’s best-kept secrets, and proved to be an elegant backdrop for the seventh annual bash. The annual festival—which took place October 14 and 15—offers behind-the-scenes access to more than 200 buildings across Chicago.