California Code, Education Code - EDC § 17490

In determining what portion of a schoolsite shall be offered for sale or lease pursuant to this article, the governing board may retain any part of the schoolsite containing structures or buildings, together with such land adjacent thereto which, as determined by the governing board, must be included in order to avoid reducing the value of that part of the schoolsite containing such structures or buildings to less than 50 percent of fair market value.