21In determining a question with respect to compensation claimed in consequence of the compulsory purchase of land under this Order, the tribunal shall not take into account—
(a)any interest in land, or
(b)any enhancement of the value of any interest in land, by reason of any building erected, works executed or improvement or alteration made (whether on the land purchased or on any other land with which the claimant is, or was at the time of the erection, executing or making of the building, works, improvement or alteration, directly or indirectly concerned),
if the tribunal is satisfied that the creation of the interest, the erection of the building, the execution of the works, or the making of the improvement or alteration, as the case may be, was not reasonably necessary andwas undertaken with a view to obtaining compensation or increased compensation.