21Use and improvement(1)

The recipient must pay the other party a reasonable amount for any use which the recipient made of the benefit (except in so far as the recipient is liable to pay compensation to the other party under section 20(2) in respect of that use).

(2)

If a recipient improved a benefit which the recipient is required by section 18(4) to return, the recipient has a right to payment for the value of the improvement (provided that the other party could readily obtain that value by dealing with the benefit) unless—

(a)

the making of the improvement was in itself a breach of the contract, or

(b)

the recipient made the improvement when the recipient knew, or ought to have known, that the benefit would require to be returned.