Well, EU isn't just one place. In Poland for instance building is very deregulated with very few cities having any kind of zones - basically if you can buy some

Well, EU isn't just one place. In Poland for instance building is very deregulated with very few cities having any kind of zones - basically if you can buy some land(and land is cheap) then you can build your own house. My own grandma built a house for herself to live in just before the pandemic - 120sqm of space, 2 beds 2 baths, with really large garden and construction+land+permits cost her a total of about $80k USD. A friend of mine just got married, they bought a piece of land from the local council for about $20k USD and are looking at buying some house plans to start building this year. From an outside perspective that seems to be a problem in many other countries - either the lack of land to build on(I can believe that in the UK but maybe not so much in US), or insane zoning laws that just straight up prohibit you from building something.