Lease agreements often contain an option for the lessee to renew the lease for a further stated period, at a specified rent or, for a method of determining the rent. Usually the lessee must have abided by all the covenants in the lease.
Current practice is for rents in the option not to be quantified but determined as market rent as agreed upon by the 2 parties. Failing agreement as determined by an independently appointed qualified valuer there is often a proviso that the option rent does not fall below the rent of the original term.