When can it be valid to exercise an option on a lease out of time?

In brief - Landlord's communication with tenant leads to tenant being deemed to have exercised the option

In a recent case, the Queensland Supreme Court decided that an option was deemed to be exercised by a tenant even though the option has been exercised beyond the last date of the period provided in the lease. The tenant was entitled to a renewal of the existing lease, not a new lease on new commercial terms.

The effect of this decision means that a landlord who communicates with their tenant after the last date for the exercise of option to the effect that a renewal of the existing lease has been granted, then this may be at the expense and detriment of the landlord, particularly if it has other plans for the premises.