Abstract: The invention consists of a pair of rectangular concrete facing connected to each other by two or more connecting cross members or webs. Each of the concrete facing members has parallel protrusions which are undercut next to the member and which are connected to the cross members by conforming each end of the connecting cross member to conform to the exterior shape of the corresponding protrusion. The invention permits easier stowage and shipment of the masonry blocks and permits on-site assembly, as well as decreasing thermal conductivity by utilization of non-masonry cross members. The cross members may be configured, or perforated, to allow utility or other service lines to be run horizontally through the walls constructed utilizing the invention.