Abstract: A composite concrete masonry unit having first and second block members separated from one another and interlocked to one another by an insulating body. The first block and a first block interior side and the second block has a second block interior side that are spaced apart from one another as substantially the same distance by the insulating portion such that there is no easy path for heat transfer through the composite concrete masonry unit. The composite concrete masonry unit is designed to minimize thermal transmittance coincidental to maximizing structural integrity when assembled into a wall.