Abstract: A compressed building block formed of a pre-mix of fly ash, either of the Class C type, or provided from sugar beet waste lime, are combined with either ground or pulverized wood and/or chips, or with fine sand, having a small amount of Portland cement added thereto, moisturized, and then either extruded or compressed in a press into the configuration of a block. A fire retardant, and an insecticide, may be added to the composition, to provide the formed block with further beneficial attributes. The blocks may be formed by a system for extruding such blocks from the formulation, or they may be formed by means of a hydraulic or other press and pressed into the configuration of the desired block, needed for the construction.