A precast wall system comprising: a first plurality of horizontally interconnected precast panels (2900a-h), each precast panel having a top end plate, a bottom end plate, a plurality of vertical bars disposed between the end plates, a cementitious material encasing the vertical bars and defining a plurality of sides of the respective panel, and a second plurality of horizontally interconnected precast panels (2902a-h) defining a lower tier; wherein a first of the first plurality of precast panels has a first column member half defining a right side of the first panel, a second of the precast panels has a second column member half defining a left side of the second panel such that, when the right side of the first precast panel and the left side of the second precast panel are disposed horizontally adjacent to each other, the first column member half and the second column member half collectively form a column member, wherein: the first plurality of interconnected precast panels (2900a-h) are arranged adjacent to the second plurality of the interconnected precast panels (2902a-h) to define an upper tier, characterized in that: the upper tier precast panels are thinner than the lower tier precast panels; each precast panel has a plurality of corner edge and a plurality of structural angles (2302a-d), each angle is disposed along a respective one of the corner edges of the precast panel; the precast wall system further comprises a transfer member and a connection plate; the transfer member has a width equal to a change of thickness (At) of the lower and upper tier precast panels; the transfer member is affixed to the structural angle of one of the upper tier precast panels and a portion of the bottom end plate extending from the one upper precast panel, and the connection plate spans and is affixed to the transfer member and the structural angle of one of the lower precast panels vertically adjacent to the one upper precast panel. a first plurality of horizontally interconnected precast panels (2900a-h), each precast panel having a top end plate, a bottom end plate, a plurality of vertical bars disposed between the end plates, a cementitious material encasing the vertical bars and defining a plurality of sides of the respective panel, and a second plurality of horizontally interconnected precast panels (2902a-h) defining a lower tier; wherein a first of the first plurality of precast panels has a first column member half defining a right side of the first panel, a second of the precast panels has a second column member half defining a left side of the second panel such that, when the right side of the first precast panel and the left side of the second precast panel are disposed horizontally adjacent to each other, the first column member half and the second column member half collectively form a column member, wherein: the first plurality of interconnected precast panels (2900a-h) are arranged adjacent to the second plurality of the interconnected precast panels (2902a-h) to define an upper tier, characterized in that: the upper tier precast panels are thinner than the lower tier precast panels; each precast panel has a plurality of corner edge and a plurality of structural angles (2302a-d), each angle is disposed along a respective one of the corner edges of the precast panel; the precast wall system further comprises a transfer member and a connection plate; the transfer member has a width equal to a change of thickness (At) of the lower and upper tier precast panels; the transfer member is affixed to the structural angle of one of the upper tier precast panels and a portion of the bottom end plate extending from the one upper precast panel, and the connection plate spans and is affixed to the transfer member and the structural angle of one of the lower precast panels vertically adjacent to the one upper precast panel. the first plurality of interconnected precast panels (2900a-h) are arranged adjacent to the second plurality of the interconnected precast panels (2902a-h) to define an upper tier, characterized in that: the upper tier precast panels are thinner than the lower tier precast panels; each precast panel has a plurality of corner edge and a plurality of structural angles (2302a-d), each angle is disposed along a respective one of the corner edges of the precast panel; the precast wall system further comprises a transfer member and a connection plate; the transfer member has a width equal to a change of thickness (At) of the lower and upper tier precast panels; the transfer member is affixed to the structural angle of one of the upper tier precast panels and a portion of the bottom end plate extending from the one upper precast panel, and the connection plate spans and is affixed to the transfer member and the structural angle of one of the lower precast panels vertically adjacent to the one upper precast panel.