The answer to this depends on whether the tenant has security of tenure or not.
If the lease is contracted out of the Landlord and Tenant Act, it is recommended that discussions are had with the landlord/tenant six to twelve months prior to expiry of the lease, to ensure a further lease is put in place which will guarantee occupation for a further period of time.
This provides comfort to the tenant knowing they have occupation for a set length of time, meanwhile for the landlord, it adds value to the property by having a secure income stream.
From the view of the landlord, if the lease is within the Act and there has been appreciation in the market, a Section 25 Notice should be served no later than six months before expiry of the lease, or no earlier than 12 months prior, to ensure a rental uplift can be achieved at expiry.
If, however, the market has declined, it would be beneficial to keep the tenant holding over, in order to maintain the higher income stream. However, the market value of the property would be compromised due to reduced security as the tenant would only have to serve three months’ notice to vacate.
From the tenant’s point of view, if the market rent is higher than what they are currently paying, holding over would be beneficial, but if the market rent has declined, a Section 26 Notice would, in theory, ensure a lower rent is achieved at expiry. The best approach would really depend on whether security of income or occupation is preferable.