Should I replace my windows with UPVC

Absolutely agree GSM. We have lived in our Listed home for 25 years and apart from our recent hiccup never had a problem with doing anything we wish to do. But we both have a lifetime preference for older properties, have owned several 19th century properties and understand the construction and maintenance of older buldings and understand how listing works

Shortly after we moved in a young couple bought a small listed house down the road and went at the renovation as if it was any old house.

We needed the then Conservation Officers assistance and he was telling us he was there almost daily telling them to undo what they had done the previous day. They were expecting to take structural timbers out and they painted, or rather varnished all the carved oak window frames, which were one of the reasons the house was listed and then had to strip it all off. They sold within a year and the new owners understood what they were doing. They renovated carefully and have since extended the property.

New windows are very expensive so I wouldn't replace them if you might move. When I moved, my windows needed replacing but the Estate Agents advised me not to do anything with them. I could just have afforded upvc and buyers might have taken them out and replaced with wooden, so wasted my money. Where I live now, most people have upvc and many have dark windows.