Interesting. Thanks for the post.
I’m curious as to the motivation to remodel/renovate these bunkers vs. demolishing them & build a more appropriate building.
I suppose the thick concrete walls insulate well, but they also waste space. Plumbing, A/C, & electrical installation & modifications would seem to be a problem.
Albania's nut jub Hoxha regime was so paranoid he built bunkers and concrete pill boxes everywhere to the point where it is not cost effective to demolish. Albanian beaches are littered with one or two man pillboxes. I think I read where those are used for beach front changing rooms in some cases.