This report considers the costs of three types of extended school year programs--all modifications of the quarter system--and compares these costs to the regular program. Compared against the traditional approach are: (1) a quarter system in which students attend three quarters a year and are off one quarter, meaning that 75% of all students are in school at any one time; (2) a quarter program in which attendance for all is mandatory, fall through spring, with summer attendance being optional; and (3) a quarter program in which attendance for all students is manadatory, fall through spring, except for those students attending the optional summer quarter. Conclusions indicate that by extending the school year, space can be saved and capital expenditures postponed. However, plans that bring about classroom savings cost more to operate, and within a few years all capital savings are eaten up in operating costs. A review of the literature, facility use information, classroom data, and attendance calendars are included. (Author/DN)