An assembling device for manufacturing a panel assembly, - wherein the panel assembly includes a plurality of wooden slats (101, 103, 105... 111, 113, 115...) and insulation panels (102, 104, 106...), each wooden slat having a given length (L 101) and a given straightness (S 101), - wherein the assembling device includes at least two tooling systems (2, 3), wherein each tooling system includes an articulated arm (2A, 3A) and a multifunctional tool (2B, 3B) disposed at the end of the articulated arm, and wherein the assembling device further includes a tooling controller communicatively coupled to the tooling systems (2, 3) and programmed to instruct the tooling systems (2, 3) to operate the wooden slats (101, 103...) and the insulation panels (102, 104...) in order to assemble the panel assembly, characterized in that each tooling system (2, 3) further include: - wooden slat gripping means (21, 31) configured to grip a wooden slat, and having a centerline (C 21, C 31), - wooden slat positioning means (2A, 3A) configured to position the gripped wooden slat at the appropriate place on the panel assembly, - wooden slat securing means (23, 33) configured to secure the positioned wooden slat to at least one other wooden slat, - insulation panel gripping means (24, 34) configured to grip an insulation panel, - insulation panel positioning means (2A, 3A) configured to position the gripped insulation panel at the appropriate place on the panel assembly, and in that the tooling systems (2, 3) are instructed by the tooling controller so that, if the length of a wooden slat (L 101) exceeds a predetermined threshold, the wooden slat gripping means (21, 31) grip the wooden slat at different parts (101A, 101B) and move relatively to each other in order to align their centerlines (C 21, C 31) and correct the straightness of the wooden slat (S 101). - wherein the panel assembly includes a plurality of wooden slats (101, 103, 105... 111, 113, 115...) and insulation panels (102, 104, 106...), each wooden slat having a given length (L 101) and a given straightness (S 101), - wherein the assembling device includes at least two tooling systems (2, 3), wherein each tooling system includes an articulated arm (2A, 3A) and a multifunctional tool (2B, 3B) disposed at the end of the articulated arm, and wherein the assembling device further includes a tooling controller communicatively coupled to the tooling systems (2, 3) and programmed to instruct the tooling systems (2, 3) to operate the wooden slats (101, 103...) and the insulation panels (102, 104...) in order to assemble the panel assembly, - wooden slat gripping means (21, 31) configured to grip a wooden slat, and having a centerline (C 21, C 31), - wooden slat positioning means (2A, 3A) configured to position the gripped wooden slat at the appropriate place on the panel assembly, - wooden slat securing means (23, 33) configured to secure the positioned wooden slat to at least one other wooden slat, - insulation panel gripping means (24, 34) configured to grip an insulation panel, - insulation panel positioning means (2A, 3A) configured to position the gripped insulation panel at the appropriate place on the panel assembly,