Boswell v Crucible Steel Co. 
The tenant had entered into a lease to ' keep the inside of the demised premises including all landlord's fixtures in good repair'. Much of the external elevations consisted of fixed, unopenable, glazing. Seven of the glazing panels were damaged and required replacement.
The tenant sought to avoid the obligation to replace the panels by arguing that the glazing was a 'Landlord's Fixture'. The Court of Appeal rejected this argument.
Bankes L.J. said
"It is impossible to say that windows such as these, forming part of the original structure of the house, are landlord's fixtures. The County Court judge was wrong in holding that these windows were not part of the walls of the house."
Scutton L.J. said
"The meaning of the term "tenant's fixtures" is well understood, but I have always had difficulty in understanding what is meant by "landlord's fixtures". But at all events it seems to me clear that that expression cannot include a thing which forms part of the original structure of the building. It must be regarded as confined to things which have been brought into the house and affixed to the freehold after the structure is completed. If these windows could be treated as landlord's fixtures, the whole house would be a landlord's fixture".
Atkin L.J. said
". . . I am quite satisfied that they are not landlord's fixtures, and for the simple reason that they are not fixtures at all in the sense in which that term is generally understood. A fixture, as that term is used in connection with the house, means something which has been affixed to the freehold as accessory to the house. It does not include things which were made part of the house itself in the course of its construction. And the expression "landlords fixtures", as I understand it, covers all hose chattels which have been so affixed by way of addition to the original structure and were so affixed either by the landlord, or if by the tenant, under circumstances in which they were not removable by him. As these windows were part of the original structure, representing the walls of the house, so that without them there would be nothing that could be described as a warehouse at all, they cannot come under the head of landlord's fixtures. If they could, every brick used in the building would be a landlord's fixture"