Performance and Design. The Insultech™ ICMU (Insulated Concrete Masonry Unit) Wall System, part of the Echelon Masonry™ portfolio from Oldcastle Artchitectural®, is a revolutionary new approach to traditional block wall construction. This 100% thermally broken masonry unit offers high thermal efficiency using pre-assembled structural units and a BASF Neopor® insulation insert -achieving a 15.2 R value while offering a multitude of design options in both standard finishes and the complete line of Trenwyth® architectural blocks.