In this chapter we see one of the central themes explored in more depth: civilisation vs savagery. You are right therefore to see building huts as being symbolic of the wider theme of civilisation and some of the boys' attempts (namely Ralph) to create civilisation rather than slide into savagery on the island. However it is highly significant that despite the agreement the boys have been able to reach about what they need to do, it is only Ralph and Simon who actually do anything about putting their plans into practice. Even then, their work is not good work, as the huts fall down. This perhaps foreshadows the collapse of civilisation on the island later in the novel.
Of course, representing savagery is Jack and his desire to hunt. Yet interestingly at this stage, the forces of civilisation still seem to win out. Jack is forced to justify his decision to hunt and not be involved in building the huts by referring to the greater good of the community rather than being honest about his bloodlust and the joy of hunting.