ChD 24 January 1990. Action raising three questions on construction of a rent review clause in a 24-year lease. The first was as to the use of the premises attributable to the hypothetical tenant; there had been, since 1988, planning permission for general office use. The tenants relied on the parcels, a qualified user covenant and an odd clause prohibiting development as restricting user by the hypothetical tenant. ChD rejected these attempts to cut down the effect of the permission for office use. The second question concerned the length of the term for which the hypothetical letting was assumed to be granted. Was this a term equal to the residue of the actual lease at the review date, namely five years, or a term equal to the 24 years originally granted?. ChD held that it was for a term of five years only. The third question was as to the date from which rent at the reviewed date started to accrue. ChD held that the rent when determined began to accrue at the new rate from commenc