You might want to have a look at straw panel construction. There's several across the EU. https://ecococon.eu/ https://ecococon.eu/ is the major one. Not affil

You might want to have a look at straw panel construction. There's several across the EU. https://ecococon.eu/ https://ecococon.eu/ is the major one. Not affiliated with them. I built the walls of our summer house out of jumbo straw bales straight from the farm.