A carpenter (or chippy) is another skilled individual. Just basic carpentry is not sufficient and to enter the film world and experience is essential. Building a film set requires special knowledge as some elements need to be moved quickly and others safe to stand on. It might sound strange but it's often difficult to differentiate between the two. If a floor can be laid prior to building the walls it can save time cutting it in, a door frame needs strapping prior to moving, a wall flat needs fixing flat on the floor before lifting etc. etc.