If it’s an old building, you might also want to look at a more sympathetic solution that works really well and allows the fabric to breath.
Subject covered before below (sorry, not sure how to paste the link properly but it talks to using insulating lime base plaster with hemp)
https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.survivefrance.com/t/wall-insulation-with-hemp-and-lime/3652&ved=2ahUKEwiCmPmXj6yLAxWnKvsDHd7JEVEQFnoECBEQAQ&usg=AOvVaw3enPNaQqRXnjFTFgB612zg
And:
While I was browsing the forum, I noticed a posting some time ago asking for information on hemp-lime insulating render.
This might come a little late to respond to the original enquiry, but with the general interest in building and renovation, I wanted to answer some of the questions and tackle some of the misconceptions regarding the use of hemp-lime insulating render in renovations compared with glass wool, stud and plasterboard.
I have a lot of personal experience of both of these solutions, the first being with glass wool and plasterboard, when I started to renovate our own house ten years ago. At that time I had very little experience in renovating cob and stone buildings and since everyone I knew seemed to be using glass wool and plasterboard, I followed suit.
I had my doubts from the beginning as to whether I was doing the right thing and began to research other possibilities.
I’ve been fascinated by bio- sourced materials in building for years and when I came across he…
I have an old 18th Century Farmhouse and in the process of improving the roof insulation with wood wool, replacing about 40 windows from single to double and replastering some walls will insulating plaster. The Wedi panels are really cool to use to form swish shower rooms but pricey if you need to straighten out walls with metal framing etc.
Good luck though!