1171. Adjustment of rateable value.

Where the tenant1, or any previous tenant, has made or contributed to the cost of an improvement on the premises2 comprised in the tenancy3, and the improvement has been made by the execution of works amounting to structural alteration, extension or addition, then, if the tenant serves on the landlord4 a notice in the prescribed form5 requiring him to agree a reduction, their rateable value6 must be reduced by such amount, if any, as may be agreed or determined in accordance with the following provisions7.

The amount of any such reduction may at any time be agreed in writing between