45. Work done by lessees.

If the terms subject to which a lease1 is granted impose on the tenant an obligation to carry out any work2 on the premises3, the lease is treated4 as requiring the payment of a premium5, to the landlord, in addition to any other premium, of an amount equal to the amount by which the value of the landlord's estate or interest immediately after the commencement of the lease exceeds what its then value would have been if those terms did not impose that obligation on the tenant