Deciding which preliminary school building options to submit to the state will be the goal of a joint meeting of the Board of Selectmen and the School Committee on Sept. 9. Town officials are considering various approaches to address the problem of overcrowded and outdated schools. As part of the feasibility study, which is being paid partly by the state, the town must provide options to the Massachusetts School Building Authority for initial review. A plan for a middle school and high school campus at the site of the current high school is among the favored options. A detailed proposal is expected to be presented to Town Meeting next year for approval.