Abstract: The present invention discloses a method of manufacturing integrated modular structure using a rotomolding process. The method comprises preparing at least a pair of molds embedded with at least one electric harness, wherein the pair of molds having a base mold and a first mold joined to form an enclosure, filling a first material in the base mold of the pair of molds, providing a heating and cooling cycle, wherein during heating at least the pair of molds being rotated for evenly spreading the molten first material and embedding the electric harness in the molten first material, obtaining a first molded part yielded by at least the pair of molds, and obtaining a second molded part yielded by at least a pair of molds, thereby the first molded part, the second molded part and the at least one embedded electric harness together forming the integrated modular structure.