A precast composite wall structure and method for forming the wall structure are disclosed. The method includes providing a casting bed defining a plurality of shapes corresponding to a three-dimensional outer surface of a wall structure, placing a first layer of uncured concrete to conform to the shapes defined by the lower surface, positioning a forming member in overlying relation above the frame, the forming member defining a plurality of rectangular-shaped channels therebetween, positioning a stud frame within the casting bed along the forming member, placing a second layer of uncured concrete within the casting bed to conform to the rectangular-shaped channels between the rectangular protrusions, and allowing the concrete to cure.