nostr:npub1g56s7a4hpexkuc6pk0xjzhws6nt5sc5z6aekw60naxmq9txjrtjs42czl2

I'm in the US but I think you probably have IKEA there too. They make shelves that are braced by a pole bolted to the ceiling and floor that are great for this application.

The downside to this kind of shelf is needing tons of bookend to hold your books up.

We made walls of books, creating a room within our large formerly open plan living room. Had it for 15 years now, still love it.

Or did you want something more case-like with sides? Might require a carpenter.