ChD 3 July 1992. Two applications by originating summons, firstly by the plaintiff landlord (X) for a declaration as to the rent payable under a lease of shop premises and secondly by the defendant tenants (Y) in pursuant to s27 of the Arbitration Act 1950 to extend the time for commencement of arbitration proceedings concerning the proper rental valuation. In the first case, in accordance with the rent review provisions in the lease, the landlords served a notice on 7 July 1988 specifying a annual rent of £19.500. The rent review clause provided that tenants could serve a counternotice within three months as to which time was of essence. On 15 August 1989, the landlord served a second rent review notice specifying £23,000. On 12 February 1990, Y decided to appoint an arbitrator. X contended that in the absence of a counternotice before 7 October 1988, the rent was £19.500 whilst Y argued that X had waived their right to rely on time constraints. Held that X was entitled to a declara