Abstract: A composite building block with a connective structure between the inner and outer wall units is presented. The wall units can be made of cement, clay brick, or similar materials. The connective structure is made of a material different than the wall units and may be integrally formed per the requirements of a particular wall construction project. In one embodiment, the connective structure comprises a center form, and one or more arms have connectors that connect to corresponding connectors integrally formed on the wall units. The center form may partition the cavity between the inner and outer wall units into two or more cavities, which may then be partially filled with, for example, insulative material or load-bearing materials, such as concrete.