A load bearing wall is formed in a building structure by a number of prefabricated modular reinforced concrete wall panels (1) mounted end to end in an upright orientation on a foundation or floor of the building. Each wall panel (1) has a reinforced concrete body (2). At least one tie bar receiver slot (10) extends upwardly into the body (2) from the bottom edge (5) of the body (2) for cooperation with and reception of tie bars during wall construction. A grouting duct (25) extends outwardly from an inner end (21) of the slot (10) to a front face (3) of the body (2) to allow back filling of the receiver slot (10) with grout. One or more lifting bars (12) are embedded in the wall panel (1) and project upwardly at a top (6) of the wall panel (1). The lifting bars (12) aid handling and engage with tie bars.