Speaking of hay for insulation, if Ukraine still makes the older rectangular straw bales instead of the big round ones mostly made in the US now, here is good information. Hay or straw bales homes were often built for the first winter by homesteaders in the US mid west prairie country. They were so warm in winter people often continued to live in them and some were even in use after 100 years. Hay is cattle food, straw is stems left after harvest of things like wheat, and is not edible.
Here is the Google page for “Straw Bale Homes in Wisconsin”. Google also had pages for other states, but Wisconsin was the coldest. There were a number of useful articles:
This link is detailed description of a family building a legal financed straw bale home. Next I will try to find a simpler more basic emergency shelter.
doorcountypulse.com/a-house-of-straw/ (illustrated)
Basic emergency straw bale shelter, Google links:
https://www.google.com/search?q=basic+emergency+straw+bale+shelter&rlz=1CAJCUZ_enUS847&oq=basic+emergency+straw+bale+shelter&aqs=chrome..69i57j33i160.16689j0j7&sourceid=chrome&ie=UTF-8
Basic emergency shelter: (Uses 65 to 72 standard bales)
https://strawbaleplans.wordpress.com/2009/03/08/straw-bale-emergency-shelter/?unapproved=3619&moderation-hash=c564b63addaa441199f1c2a81f9b52c4#comment-3619
Another basic shelter site:
https://naturalbuildingblog.com/emergency-straw-bale-shelter-links/?unapproved=1578735&moderation-hash=cbac22322365116a1869e83b958967df#comment-1578735
Thank you for info. I will share. Kind of reminds me of Mary & Joseph with baby Jesus in the stable :)
Usually round cylinders from what i remember, but where they don’t have the machinery you might see almost pyramid piles. In this weather, pykrite could be quite convenient AND resilient to some artillery.