During the lifetime of a lease an application by a tenant for consent to alterations is a common occurrence. In some cases landlords may refuse consent, particularly where there is a risk to their reversionary interest and/or the proposed alterations are prohibited by the terms of the lease.
Although landlords are not obliged by statute to give reasons for refusing consent (unlike, for example, where a tenant makes an application to assign its lease) it is a good idea to do so. This is because if the tenant subsequently challenges the decision by its landlord in court the landlord must show the reasons that supported its decision at the time it refused consent. Obviously this is much easier to do if the reasons are set out clearly and fully in writing.
This approach also has the benefit of making it easier for the tenant to address the concerns that the landlord has or revise its works programme.
For more on this subject see the recently released Protocol for Applications for Consent to Carry Out Alterations.