A method for growing organically derived building materials in the form of a moldable substrate that can be engineered to serve a wide range of manufacturing and construction applications is presented. In particular, the embodiments consider a plurality of fungal molded shapes preferably grown from fungal inoculum and mechanically compressed at least once during the growing process as well as integration of structure support members to the fungal structure. The present invention provides a fungal substrate which could be molded, and easily and cheaply preprocessed to precise geometric specifications. The organically derived building materials also incorporate layers of structural reinforcements to improve load bearing and other structural capacities.