To save me high jacking someone's quite sensible topic, I thought I would have a quick look at straw as a building material.   It is often touted as a sustainable, low energy input material, so I thought I would look up how much straw is harvested from a hectare (10,000 m2) of land, a nice size garden, but only 1/13,293,000 of the land area of England. Taking wheat straw, it is an average if 4 tonnes/hectare, the wheat itself was 7.8 tonnes (both 2021 figures and from here).