Abstract: A concrete component connecting system includes first and second precast components (112, 118) adapted to be arranged in abutting relationship in an assembled configuration, the first and second precast concrete (112, 118) having respective first and second edges (116, 120) which face each other in the assembled configuration. A locking mechanism (122, 126) is also provided including mutually engageable components disposed at the facing edges (116,120). The locking mechanism (122, 126) including a remote actuating means to effect locking of the mutually engageable components (122, 126) at or beyond a third edge of one of the first and second precast components (112, 118), to secure the first and second precast components (112, 118) together. One of the building components may comprise a building panel (12) which is generally planar in form. The building panel (12) has a core (14) which is substantially planar in form with opposite sides and is substantially aligned with the plane of the building panel.