What follows is my analysis of the position. It should not be treated as gospel.
It is often asserted that a landlord, even if the tenant has agreed to it in the tenancy agreement or lease, may not enter premises without the consent of the tenant. Whilst on the whole it is wise for a landlord (and especially a landlord of residential premises) to proceed on the basis that that is the law, I do not think it is in fact the law.
There is no rule of law that says that a landlord may not exercise any right of entry he reserves. A tenant must of course not be harassed. Apart from that he has a right to quiet enjoyment, but that right needs to be read as if it were qualified by any right reserved that allows the landlord to enter, so long as he behaves reasonably. It is not easy to say what is reasonable. Since the exercise of the right is not dependent upon a court saying it can be exercised there must be circumstances, apart from a case of genuine emergency, where it is not unreasonable for a landlord to enter without consent and even where consent is refused, but it is a brave landlord who thinks he knows what the circumstances are.
If you want a more detailed consideration of the question, read on.
To put the question is a wider context, no interest in land, whether freehold or leasehold, is ever absolute in the sense that the whole world can be excluded or that the law permits you to do what you like on your own land. First and obviously you cannot commit a crime. The law allows aircraft to invade your airspace. The ownership of mines and minerals such as coal, gas and oil is determined by statute and such as gold and silver by the common law. You may not do anything on your land which interferes with any natural rights of drainage or support enjoyed by your neighbour. The law does not allow you to commit a legal nuisance on your land. Certain activities or changes may require the permission of a competent authority. There are any number of statutory rights of entry.
When it comes to land law, which is private and not public law, rights exercisable over land may be agreed (and in some cases implied) and a landowner may agree to restrict the use of his land in some way. In particular, rights of access (not to be confused with rights of way) may be granted or reserved.
If the owner of a property wishes to go onto his neighbour's land to carry out repairs there are two possibilities:
A. He has an easement that allows him to go onto the land. The easement can only be exercised for the purposes stated and according to the terms of the grant and must in any event be exercised reasonably. If the neighbour declines to allow or prevents access an application may be made to the court to enforce the right.
B. He does not have an easement and the neighbour refuses consent. In that case, if certain conditions are fulfilled, the court may, if asked, make an order allowing access under the Access to Neighbouring Land Act 1992. Access is then allowed for the purposes specified in and subject to any conditions imposed by the order. Once the works permitted have been carried out and all conditions complied with the order effectively becomes a dead letter and any future access requires a new order.
The difference between A and B is that in A the right of access exists without the intervention of the court, even if it may prove necessary to ask the court to enforce the right, but that in B the right only exists by virtue of the court order. This distinction should be kept in mind.
When it comes to tenancies the starting point is this: a tenancy is an arrangement in which the landlord gives up his right to exclusive possession (that is possession in the sense of occupation) and hands it to the tenant in exchange for (usually) money. Ignoring the intervention of statutes such as the Protection From Eviction Act 1977, the tenant's right to exclusive possession is strengthened by two things:
1.The landlord's covenant for quiet enjoyment, which if not express is implied. (Theoretically, I suppose it may be expressly excluded, but I have never heard of this being done.) This covenant is essentially a promise by the landlord not to interfere with the tenant's enjoyment of the property. It is a right that arises as a matter of contract; a breach by a landlord of his covenant for quiet enjoyment is not a tort. The distinction is important because the remedies are different. Whilst in an action for both breach of contract and in tort the court may make an order restraining the defendant from repeating the action complained of, the measure or quantum of damages is different. Simplifying and without going into the matter in detail (something I am in any event not competent to do since I was never a litigator) where there is a breach of contract the measure of damages is the financial loss suffered. It is important to bear this in mind.
2.The rule that a landlord may not derogate from his grant, that is that he cannot give something with one hand and take it away with another.
There is some overlap between a breach of a covenant for quiet enjoyment and derogation from grant, and some actions may amount to both. However, no discussion is required for the purpose of this post and any further reference to a breach of a covenant for quiet enjoyment should be taken to include a reference to a derogation from grant.
In a tenancy agreement or lease a landlord may do one of two things, or may do both:
(a) impose an obligation on the tenant to allow access for specified purposes
(b) reserve a right of entry for specified purposes.
The effect is the same, which is that the landlord has what we may call “the landlord's right of access” - or at least that is what I hope to show.
There is no statute or any common law rule that says that the landlord's right of access is void or unenforceable. Indeed, in certain cases the law implies a landlord's right of access into the terms of a tenancy. It would be nonsense for statute to imply a right that was void or unenforceable. It cannot be the case that the right only exists where the court says it exists (like a right granted by the court under the Access to Neighbouring Land Act 1992) because there is no statute that allows the court to create such a right. Further, it cannot be the case that you can ask the court to enforce a right that does not exist. I think therefore that we can say that the landlord's right of access exists by reason of it having been agreed, whether expressly or impliedly, and that it exists from the moment that it is agreed.