The state board of education may issue an order authorizing any school district to vote bonds for the purpose of purchasing or improving a site or sites, constructing, furnishing, equipping, repairing, remodeling or making additions to buildings necessary for school district purposes, including housing and boarding pupils enrolled in an area vocational school operated under the board of education of the school district, or purchasing school buses to an amount to be determined by the state board of education, and in addition to, the amount of bonds which the district may be otherwise authorized to issue.