In Earl of Plymouth v Rees (2019) EWHC 1008 (Ch) the Court set out the interpretation principles applicable to a clause in a lease that reserved rights to the landlord, as follows:-
(1) An exception or reservation would be construed, if possible to preserve its validity; (2) it should be construed as restrictively as required to avoid derogating from a grant or conflicting with the covenant for quiet enjoyment, which was the “irreducible minimum” implicit in a lease; (3) there was no further rule that a reservation should be construed restrictively against a landlord; (4) standard construction principles would generally lead to the expectation that substantial qualification of the tenant’s rights to exclusive possession and quiet enjoyment would clearly appear in the lease, and the broad wording of reservations might have a more restricted meaning in context; (5) a reservation which could not be construed consistently with the irreducible minimum implicit in a lease would be struck down as repugnant to the lease; (6) the contra proferentem rule only operated if the reservation was ambiguous; (7) it only applied where the court could not otherwise decide between two or more constructions which were all consistent with the irreducible minimum, because an inconsistent construction would have been struck down or rejected in favour of a consistent construction; (8) if the rule was used, its correct interpretation was that a reservation operated as a re-grant by the tenant, so the reservation fell to be construed against the tenant, as the proferens.