3. (1) Notwithstanding anything contained in any other law for the time being in force, or in any agreement, no person shall, without the previous sanction of an Authorised Officer, construct or re-construct or make addition or alternation to any building, or excavate or re-excavate any tank ¹[* * *] within the area to which this Act applies; and such sanction shall be subject to such terms and conditions as the Authorised Officer may think fit to impose: Provided that such sanction shall remain valid for three years from the date of sanction and on the expiry of the period, the application shall have to apply and obtain a fresh sanction. (1a) Notwithstanding anything contained in sub-section (1), all sanctions obtained during the 12 months immediately preceding the 30th September, 1958, shall be deemed to have expired and no such construction or excavation shall be made without obtaining fresh sanction. Explanation.- For the purpose of obtaining fresh sanction under sub-section (1) or sub-section (1a), no fresh sanction shall have to be obtained for the construction of buildings where the construction has been made up to 4 feet above plinth level. (2) The Government may, by notification in the official Gazette, direct that the power of an Authorised Officer under sub-section (1) shall be exercised by a Committee in such area as may be specified in the notification. (3) When a notification under sub-section (2) has been issued, the Authorised Officer shall not exercise the power conferred on him by sub-section (1) in the area to which the said notification relates. (4) The provisions of sub-section (1) shall not apply to normal repairs to existing building.