What is "core-and-veneer"

Core-and-veneer, brick and rubble, wall and rubble, ashlar and rubble, and emplekton all refer to a building technique where two parallel walls are constructed and the core between them is filled with rubble or other infill, creating one thick wall. Originally, and in later poorly constructed walls, the rubble was not consolidated. Later, mortar and cement were used to consolidate the core rubble and produce studier construction.

Modern masonry still uses core and veneer walls; however, the core is now generally concrete block instead of rubble, and moisture barriers are included. Often such walls end up as cavity walls by the inclusion of space between the external veneer and the core in order to provide for moisture and thermal control.