WINONA, Minn.  – School Superintendent Brad Berzinski proposed shortening the school year for the district’s three elementary schools by one week this spring. Berzinski said that construction crews need to start installation of new  heating and cooling systems at Jefferson and Washington-Kosciusko schools, a summer project, as early as possible. The high school and middle schools woudn’t be affected. Berzinski’s proposal is on the School Board agenda next week. If approved, the school year for early childhood through fourth grade would end May 30 instead of June 6. The new calendar also would shorten spring semester for the district’s third elementary school, in Goodview. To avoid disruption of Early Childhood and Key Kids programs, those students would go to Goodview for the week. Berzinski said the changes would not interfere with the state-required minimum number of teaching days. He noted that it may be necessary to delay the start of  fall classes for crews to accommodate the heating-cooling projects.