I see a number of EU citizens here having problems finding affordable property for alternative building or for self-sufficient living.
One option I want to suggest is to look further afield but remain in the EU - Bulgaria!
Bulgaria is a truly wonderful country and has a huge number of abandoned small-holdings in villages available at very low prices compared to western Europe. The cost of living is also lowest in Europe.
Provided there is an existing legal dwelling on the property, even if it's falling down, you are likely to find you'll have no problem adding an alternative construction to the property. Most village properties will have a legal dwelling or
footprint of a dwelling shown on the official map. If so, you can just go ahead and build pretty much anything, either on the footprint of the older building or as a supplemental building. Keep things low-key and there are no concerns about permits. It's not like Wales where they will fly drones or send inspectors out looking for properties to take legal action against! Or one can repair the existing mudbrick dwelling to live in.
If you want privacy, properties on the outskirts of a village but still within village boundaries can often be quite isolated and come with a decent amount of
land.
Plus, you will be welcomed! Locals don't want their villages to shrink to nothing and die, so they need and welcome newcomers. There is a strong tradition of self-sufficiency which is still alive in most villages.
I just want to put the suggestion out there. I see so many people discussing not being able to afford land in the "usual" places in Europe like Wales or Portugal, when in Bulgaria a few thousand euro will buy a basic village house in need of some repair work on a couple of overgrown decares of land!
I love, love, LOVE the place I bought in a rural part of North-east Bulgaria, and feel so blessed to have it.
Bulgaria offers wonderful options for those with a pioneer spirit and a lower budget, especially EU citizens who will have no problem getting residency.