The tenants in the house next door have put a window in the side of their bungalow which forms the boundary with our property, with the result that they can see right into our kitchen and bathroom. The previous tenant signed an agreement preventing him from doing this, but we have contacted the landlord and he doesn’t want to know.
There’s probably a clause in your neighbours’ lease requiring them to obtain the landlord’s consent before carrying out any building work but you can’t make the landlord enforce the terms of the lease. Unless the installation of the window contravenes planning laws or building regulations or a covenant in the title deeds to the house, you may have to invest in some net curtains. You have no automatic right to privacy.