(3)Notwithstanding anything contained in sub-section (1), in all cases in which any land or building is for the first time assessed, or the annual valuation of any land or building is proposed to be increased, written notice stating the reasons therefore, shall be served on the owner or any lessee, sub-lessee, or occupier of such land or building and the notice shall specify the time, not being less than thirty days from the date of service of the notice, within which objections, if any, to the valuation may be filed.