We currently rent a house which has a kitchen extension. It is more of a sun room so has a lot of glass windows, in fact 3 sides of it is glass, but has been put at the end of the kitchen so we use it for our dining table. I would say that about 90% of the extension is glass. The lower half is fitted with that ugly bumpy stuff you sometimes see in schools with the wire grid. But the top half (more than half the total area) is plain non-safety glass. I have trawled google and have found that all glass doors must have safety glass as well as "any vulnerable point in the building" but does this apply to large windows? One of the windows has now developed a large crack which is spreading and I'm worried the whole window is going to break at some point. Does the landlord have to replace these windows?