UPVC window in a Listed building/G2?

Here are the FAQ https://hotfrp.com/faq, it explains why fiberglass windows are good.

Reply to the comment left by Hoff Teng at 16/05/2023 - 09:18
A building is listed to protect its architectural features - which is why replacement is resisted (strongly) if a window is in place the LA will not give consent, I know that there is someone on here who has consent but this is extremely rare and I've never come across it - they will replace if they are completely destroyed obviously and like for like - look alike. Fibre glass I doubt will be entertained. Nice idea as there is so much now in fibre glass.

Hi Reluctant Landlord
We have a Grade 11 listed building. When the developers converted it to flats in the 90`s a lot of windows/doors were replaced with UPVC, but only at the sides and back. The LA seem only concerned with what can be seen from "the highway."
We have continued and got PP etc, but never ask for the front.

Reply to the comment left by Harlequin at 01/02/2023 - 10:13
Vandalism?? I have a Grade 2 listed building and I'd like to replace my rotten wood single glazed windows with UPVC double glazed and it's certainly not vandalism. I have spent a lot of time researching and reading up on this issue.
My windows are Georgian and I can source a UPVC window that replicates the original very closely, the cills depths/heights are the same, glass sizes the same, everything is the same Inc butt joints. If you put a certain conservation style UPVC next to a new wood window the person on the Clapham Omnibus would not be able to tell the difference, so where is the vandalism? I have discovered people who are opposed to UPVC rarely have valid reasons other than, historic bias.
UPVC windows are more efficient, better U values etc and if the windows look the same...
Wood windows warp especially in a wet climate, welcome to the UK. Once the window has warped kiss and U value goodbye, it now leaks air in and out. Damp air getting in through bad wood windows isn't good for the building itself or for people health or wealth.
Of course, Historic England are still suggesting you can use a heavy curtain to stop the draught or use shutters if you have them. Neither add to the U value and both deprive you of light meaning that you need to use more electric lighting so more damage to the planet.
Secondary glazing. I think people think you only look at a window of a listed building from the outside. From the inside, my home, secondary glazing totally spoils the look of the window. From the outside, secondary glazing looks bad and spoils the look of the window.
Do you put saving the planet over the building? If you can keep the look of the building using UPVC where is the issue, except that the UPVC reduces heat loss so helps saves the planet.
Ahh...but wood windows are more environmentally friendly to make which is not necessarily the case.
Twenty years ago, UPVC windows were not good enough to be able to mimic wood windows, today they are. People old fashioned ideas and bias need to change.

I have the same dispute with our local planning board. They seem obssessed with replacing materials with near copies, never mind that a modern (longer lasting material) can look exactly the same. But when it comes to paint, I have never been asked to track down some ancient formulation - they just insist on the colour being appropriate. (ie WHAT IT LOOKS LIKE!)