ANN ARBOR, Mich. (AP) - A University of Michigan class is constructing the first student-built facility on the Ann Arbor campus, and it's made primarily out of straw bale. University of Michigan Art, Design and Environment Professor Joe Trumpey and his team of 25 students broke ground earlier this month. Trumpey says the concept is to use as many natural local materials as possible. He says the 600-square-foot building is insulated by straw bales. Adobe is also used, with an earthen floor inside. The straw building will be situated near the UM Campus Farm at the Matthaei Botanical Gardens. Trumpey says the building will give the farm a social space to host class meetings and dining events, such as farm-to-table dinners. The students expect to complete by building by the end of the month.