Appeal of Tenancy Tribunal — option to purchase agreement — Vector Gas Ltd v Bay of Plenty Energy Ltd [2010] NZSC 5. The appellants appealed a decision of the Tenancy Tribunal in which the Tribunal declined to refund a portion of the $800 per week “occupation payments” which the appellants made while living at the respondent's property. The amount of the credit claimed was the difference between the fair market rate ($695.00) during the tenancy and the $800 weekly payment. The appellants were interested in buying the property from the respondents and the respondents required additional income to pay the mortgage on the property. The agreement was written up by the parties. It provided the appellants the option to purchase, which they did not exercise. However, had the option to purchase been exercised, the purchase price they would have paid would be reduced by virtue of their payment of the weekly $800 " occupation rate". The agreement provided a complicated formula that basically provided a deduction of $10,000 for each year of occupancy prior to purchase. There was a further section of the agreement titled "Improvements and Construction" which allowed the appellants to make renovations to the property and a provision for compensation for any improvements made by the respondents. After applying the general principles relating to contractual interpretation to the agreement, the Judge ordered that the respondents credit the appellants a sum calculated at $105 per week for the period of occupancy. The decision was based on the fact the occupancy rate was not simply equivalent to rent, as it was well above market rate and was being used to offset the purchase price of the property, and that the Adjudicator erred in interpreting the "contributions" under the agreement. Further, when applying the principles of contractual interpretation, allowing the appeal accorded with the merits and justice of the case, in that there was no injustice to the respondents by receiving no more than fair market rate. Judgment Date: 14 March 2018.