A building louvre assembly (10) comprising: a louvre (14) having an elongate louvre body (18) and an elongate mounting element (20), a longitudinal extent of the elongate mounting element (20) at least in part extending alongside at least a portion of a longitudinal extent of the louvre body (18), the elongate mounting element (20) including teeth (24); and a clamp (16) for being supported by a building wall (21) or building façade, the clamp (16) having a receiver (28) for clamping on at least a portion of the elongate mounting element (20), the receiver (28) having teeth (34) configured to mesh with the teeth (24) of the elongate mounting element (20) so that the louvre (14) can be mounted at angular increments relative to the clamp (16).