We have been living in a thatched listed building, that is also in a conservation area since 1993.
We have added a two floor extension, it replaced an attached garage. We have also had an extension along the back, which replaced a narrower corrugated shed. We have also put on a conservatory.
Pretty much everything has to go through the Conservation office as well as buildings regulation. The back extension and conservatory work was 1993- 1996, with the 2 storey in 2008.
Its been very much a mixed bag. Guidelines have obviously changed over the years, and the actual conservation officer can sometimes be a little idiosyncratic, and they always trump buildings regs.
Some examples. We must retain the existing single glazed wooden windows at the front of the main house.The back extension, not visible from the road, we were allowed to put in double glazed wooden windows, but they insisted on metal conservation roof lights (twice the price of velux).The conservatory was also double glazed.
The 2storey extension had to have bespoke single glazed wooden window (both front and back) Very expensive. The back windows are not visible from the road.
The main house is thatched, the back extension and conservatory were slate, originally done to match the roof of the original attached garage.
However, when we demolished the garage we applied to reslate the new roof. But they insisted we use red clay tiles, and we had to submit the tile we wanted to use. They then insisted we use a redder tile. You go figure that one. We have rewired and replumbed throughout.
So very much a mixed bag as I said. They refuse stuff you think is very reasonable, but say yes to something you thought they’d object to. We have loathed them at times. We started to think that whatever you asked for they felt a need to say no to at least something. We have had at least one of them tell us we are merely caretakers for the future.
I don’t know if it is still possible but you used to be able to ring them up, just to talk about possible work, and they would give you an answer at the time. otherwise look up listed buildings consents on your local councils website. That will give you an idea of what they’re allowing and refusing.