Certain expenses may be declared to be improvement expenses.

(1) Any expenses incurred by the Commissioner under any provision of this Act in respect of any material of fittings supplied or work executed or thing done to, upon or in connection with some building or land which are recoverable from the owner or occupier of such building or land may, subject to the regulations, be declared to be improvement expenses if the Commissioner with the approval of the Corporation, thinks fit so to declare them, and on such declaration being made, such expenses, together with interest thereon payable under sub-section (2), shall be a charge on the premises in respect of which, or for the benefit of which, the expenses have been incurred. (2) Improvement expenses shall be recoverable in instalments of such amount not being less for any premises than twelve rupees per annum, and at such intervals as will suffice to discharge such expenses, together with interest thereon at such rate not exceeding six per centum per annum as the Standing Committee may fix from time to time, within such period not exceeding thirty years as the Commissioner with the approval of the Corporation may in each case determine. (3) The said instalments shall be payable by the occupier of the premises on which the expenses and interest thereon are so charged or, in the event of the said premises be­coming unoccupied at any time before the expiration of the period fixed for the payment of such expenses or before the sum, with interest as aforesaid, are fully paid off, by the owner for the time being of the said premises, so long as the same continue to be unoccupied.