Joanna Sykes on the scope of the doctrine of non-derogation from grant
In 1975 Lord Denning stated the principle of non-derogation from grant: “If one man agrees to confer a particular benefit on another, he must not do anything which substantially deprives the other of the enjoyment of that benefi t, because that would be to take away with one hand what is given with the other.”
In the context of landlords and tenants, where a landlord lets land for a specific purpose, then it is under an obligation not to take any steps as regards its retained land which would render the demised premises unfit or unsuitable for the purpose for which they were let.
The problem with this doctrine is that it is founded in case law and as such there is some uncertainty as to its scope and application. Certainly its scope is not confined to real estate, but for the purposes of this article I shall limit the discussion to landlord and tenant matters.
The courts have not formulated a legal test that can be applied to assist
