(1) Subject to the provisions of this Act and notwith standing any contract to the contrary, no landlord shall be entitled to charge monthly rent for any house at a figure higher than the standard rent.
(2) If at any time, after the thirty-first day of Decemb~r 1946, any addition, improvement or alteration (not being repairs within the meaning of the provisions of Section 7 below) has been effected in respect of the house at the landlord's expense, then the landlord shall be entitled to charge an increase per month over the standard rent, not exceeding ooe-twelfth of the seven and half per cent. per annum of the cost of such addition, improve ment or ,dteration, with effect from the date on which the additior', improve ment or alteration was completed.
(3) If it is not possible in any particular case to determine the standard rent of the house, or if the construction of the house was not completed before the thirty-first day of December 1946, then the monthly rent for such house shall be an amount equal to one-twelfth of the seven and half per cent. per annum of the cost of construction of the house.