Opera House Investment Pty Ltd v Devon Buildings Pty Ltd

Opera House Investment Pty Ltd (the appellant) appealed to the High Court of Australia from a decision of the Supreme Court of Victoria. The dispute concerned the interpretation of a lease covenant regarding additional rent payable by the appellant as assignee of the lease to the respondent, Devon Buildings Pty Ltd, the assignee of the reversion. The appellant argued that it was not bound to pay additional rent at a rate of 4.5% per annum on a sum of £18,131, as claimed by the respondent.

The central legal issue before the High Court was whether the respondent, as the lessor, had acted reasonably in contracting to pay an interest rate of 4.5% per annum on a mortgage of £35,000, which included the original sum of £18,131 borrowed for building costs. The lease covenant stipulated that after the expiration of the initial mortgage, the lessee would pay additional rent equivalent to the interest payable by the lessor on the borrowed moneys, at "such higher or lower rate of interest as the lessor may reasonably contract to pay on the said moneys." The appellant contended that the respondent had not acted reasonably, particularly as an offer to renew the mortgage for the original sum of £18,131 at a lower rate of 4% per annum had been available.

A majority of the High Court (Latham C.J., Starke, Evatt, and McTiernan JJ.) held that the lessor was entitled to consider its own financial interests and was not obliged to subordinate them entirely to the lessee's interests. The Court reasoned that the lessor had acted reasonably in consolidating its indebtedness, including outstanding purchase money, into a single mortgage of £35,000 at 4.5% for a five-year term. This approach was considered a prudent business decision, providing convenience and avoiding the potential difficulties of securing a separate, smaller loan at a lower rate while managing other significant financial obligations. The majority affirmed the decision of the Full Court of Victoria. Dixon J. dissented, finding that the lessor had not acted reasonably because the decision to pay a higher rate was driven by the lessor's own financial needs to cover the balance of purchase money, rather than solely by the interests of the lessee or the specific sum borrowed for the buildings.