1257. Rent payable under the new tenancy.

The new tenancy1 to be granted2 must provide that as from the original term date3 the rent payable for the house4 and premises5 shall be a rent ascertained or to be ascertained as follows:


    (1)     the rent must be a ground rent in the sense that it must represent the letting value of the site6, without including anything for the value of buildings on the site, for the uses to which the house and premises have been put since the commencement of the existing tenancy, other than uses which by the terms of the new tenancy are not permitted