A method for producing a composite construction element is disclosed. In one embodiment, the method includes the steps of: a) providing a composite construction element, which comprises a thermoplastic core layer between two fiber-reinforced thermoplastic cover layers; b) providing one or more interruptions in a fiber-reinforced thermoplastic cover layer of the panel; c) positioning a fiber-reinforced thermoplastic reinforcing layer over and/or near the interruption; d) deforming at least the edges situated along the interruption and, if desired, the thermoplastic reinforcing layer, preferably while simultaneously locally compacting the core layer, so that a thermoplastic construction element having a recess which is delimited by fiber-reinforced thermoplastic walls is obtained.