If the parties cannot agree on a statutory case, the matter is referred to the First Tier Tribunal of the Property Chamber and they will determine the price that is paid. The Property Chamber is an ‘expert’ tribunal and can make its own assessment but will initially listen to the evidence submitted by both parties. It is necessary to produce an expert valuation report and to provide expert evidence to the tribunal.
If you are progressing outside of the statute and cannot agree, then the best solution is to serve a notice and bring the matter within the statutory control of the 1993 Act. At the very least in this way you can ‘fix’ the valuation date at the date of the Notice, so that fluctuating property markets will not impact the price of your lease extension.