ChD 13 June 1986. An appeal against the decision of an arbitrator on a rent review clause in a lease. A 25 year lease was granted in 1980 at a rent of £42,025 per year, subject to upward review at five year intervals. There was no provision in the review clause that the hypothetical lease was to be on the terms of the actual lease. Neither was there an express reference in a series of assumptions, to any assumption as to rent review in the hypothetical lease. The arbitrator had assumed a hypothetical lease without rent reviews, and valued accordingly, fixing a rent at the first review period of £55,000. The arbitrator then made an alternative award of £48,500 on the basis that rent reviews were to be assumed in the hypothetical lease. The tenants, EDP, appealed, citing British Gas Corporation v Universities Superannuation Scheme Ltd (See Abstract 36103). They submitted that the review clause should be construed in the light of an underlying commercial purpose, and one of the provisio