Prime Office Space with Direct MBTA Access. Flexible Layout to accommodate Open Office or Medical Office Space Requirements. Enjoy Class A amenities without the Class A pricetag. Owned and managed by A.W. Perry and located in the heart of Downtown Crossing across from Macy’s, the Summer Exchange Building at 40 Summer Street is accessed through the lobby of 101 Arch Street. Tenants of the Summer Exchange enjoy the amenities of 101 Arch Street without having to go outside.