The importance of definitions: repair obligations
The starting point on deciding whether a feature of a building is to be repaired by the landlord or the tenant is the definitions section of the lease. Often, standard definitions are used which do not mention the distinctive features of a particular building, leading to confusion when these parts are in disrepair, or at the end of the lease when dilapidations are negotiated.
Looking specifically at windows, the case of Holiday Fellowship v Hereford  1WLR 211 dealt with whether it was a landlord or tenant obligation to repaint and repair windows and their frames. This case sets out a great many variations and factors that could lead to the windows being the tenant’s responsibility as part of their demise, or the landlord’s as part of the structure of the building. Ultimately, it was decided the answer lay in the use of language and the facts of each case. In this case, windows were not mentioned but walls were the responsibility of the landlord. It was held the windows were not part of the walls, and were swept up in the tenant’s general repair obligations.
Many variations are apparent, and the cases have been numerous. From skylights to plastic windows, window frames and bays, the courts have taken different approaches and each case has very much turned on the facts. This area has proved to be fertile ground for litigation, especially as the costs of repair in a large building can be substantial. We are left without a definitive opinion being reached on the issue, and therefore anyone seeking to rely on a case previously decided would need to be confident their lease was based on vary similar facts.
In the absence of proper definition, there is no preference the courts take, and no guidance they can rely on except that of previous cases. The contents of the rest of the lease will be very much relied on, along with a (hopefully) practical and pragmatic view by a judge.
Litigation on these issues is likely to be costly, perhaps exceeding the repair costs disputed. It is likely a great many issues are solved by either party shouldering the burden, rather than litigate. This is in most cases the most practically commercial approach when irregular features of a building have not been taken into account, but does not lead to any more certainty in case law.
Proper definitions in the lease are the simple solution. Making sure any unusual features are specifically referred can avoid any disputes later down the line. Let the lawyer drafting the lease know any quirks of your building sooner rather than later. Consider sending them photographs to set the scene. Even if the definition is not required, it is worth the certainty to both parties of knowing who is responsible for each feature, and what each should be maintaining.