CA 13 November 1986. This was an appeal by the rating authority, Westminster City Council, against a decision of the Lands Tribunal, where the contractor`s basis of valuation was applied to determine the gross value and rateable value of a hereditament occupied by Imperial College, London. The rating authority contended that the Lands Tribunal departed from the accepted method of arriving at the decapitalisation rate , as a result of which, too low a rate resulted. In particular, the rating authority submitted that the Lands Tribunal had erred in its reference to "an interest rate fixed from year to year", the allowance for inflation, the "borrower`s premium" and other comparable assets. In the CA, it was held, dismissing the appeal from the rating authority, that the Lands Tribunal had not erred in law on the contractor`s basis of valuation in; the assessment of rent, the rate of interest, discounting the effect of inflation, adopting a 1% borrower`s premium, taking into account dec