After Beaufort County voters approved a $344 million bond referendum in November, the Beaufort County Board of Education has set maximum prices for building additions at River Ridge Academy and May River High School. M.B. Kahn Construction of Columbia will build the bond referendum’s first two projects for a guaranteed maximum price of $20.9 million. Those projects include River Ridge Academy, which will add four classrooms on each of its two existing wings and add a new eight-classroom wing. May River High will add a new two-story wing containing 23 classrooms.