Upvc windows in conservation area

[Anxiouslywaitingfor]

I bought my flat 5 years ago, in a conservation area.

The windows were falling apart and part of the sales condition was for the vendor to replace the windows which he agreee to.

Recently a new neighbour moved in and informed me that my upvc windows were in breach of conservation laws and that she was going to file a complaint to the council if I didn’t replace the windows with sash ones fitting to the area.

I’m absolutely terrified that I”m going to be forced to replace the windows as I simply cannot afford to. I had no idea that the vendor had breached conservation rules and feel that I shouldn’t be penalised for his error.

I”d be very grateful for any advice on the matter from MNers who have knowledge in this sort of thing. TIA

You'd need planning permission to replace them anyway, as it's a flat, unless they were a like for like replacement. However, if development has been in place for 4 years or more then you're immune from enforcement action. Maybe dig out any evidence you have, paperwork/photos etc just in case enforcement get in contact. I really wouldn't be stressing.

Conservation area doesn't necessarily mean that you can't change the windows.
Look up conservation areas on your councils website. Is the building listed?
Anything in your documents?