(a) The municipal school budget submitted by the board of education to the governing body shall include estimates of school revenues, as well as estimates of expenditures necessary for the operation of the school system for the next fiscal period.
(b) The governing body shall have no authority to modify or delete any item of the school estimates and shall have the power to modify only the total amount of the school budget, except that in no event shall a reduction in the school budget exceed the total sum requested by the board of education from current municipal revenues.
(c) Such budget estimates shall not include any requests for the purchase of land, and the purchase, construction, reconstruction or major alteration of any building for school purposes. Requests for such improvements shall be transmitted to the governing body of the municipality or to the planning commission, in those municipalities where there is a planning commission, for review and incorporation into the capital improvement program.