(1) No new work or appliance, the estimated cost of which exceeds such amount as may be fixed by the Government in this behalf, shall be commenced or provided by the Board nor shall any contract be entered into by the Board in respect of any such new work or appliance until a plan of an estimate for such work or appliance has been submitted to, and approved by the Board; and in case the estimated cost of any such new work or appliance exceeds such amount, as may, from time to time, be fixed by the Government in this behalf, sanction of the Government to the plan and estimate shall be obtained before such work is commenced or appliance provided.
(2) Nothing in sub-section (1) shall be deemed to require further sanction of the Government in any case where the actual expenditure incurred does not exceed by more than ten per cent. of the estimated cost so sanctioned.