Under the UK's long occupational leases rents are typically reviews every five years to open market value, in order to protect investors against the effect of inflation. However the property crash of the early 1990s highlighted an anomaly in the system: rents can usually only be reviewed in an upwards direction, which means that tenants were unable to benefit from falling property values during a recession.

Under the new code of practice landlords will have to offer tenants a wider choice of lease terms, if asked. These could include longer or shorter leases or leases with more or less security of tenure. And on rent reviews the code says "Rent reviews should generally be to open market rent. But is says landlords should be prepared to offer alternatives such as upwards or downwards rent reviews or rents linked to inflation.

But tenants will have to pay for this new flexibility. The code says alternative lease clauses should be priced on a risk-adjusted basis. So if a landlord gives up some of its security of income-flow, it will be able to demand a higher rent from the outset in compensation.