Section 3(vi) in Bihar Buildings (Lease, Rent and Eviction) Control Rules, 1983
(vi)If at any time after the standard rent is fixed under the provisions of the Act any addition, improvement or alteration (not being repairs) is effected at the landlord's expenses which was not taken into consideration in fixing the standard rent, then the landlord shall be entitled to have the monthly rent increased by an amount not exceeding one-twelfth or seven-half percent per annum of the cost of such addition, improvement or alteration with effect from the date on which the addition, improvement or alteration was completed.
