The library of my childhood and teen years was one of the Carnegie-style buildings, brick, with graceful front steps curving up to the front veranda, tall columns, double white doors, and a reading room on each side of the entrance lobby. Each room had a fireplace (never a fire burning), with comfortable chairs on either side, and shelves full of books. From the lobby you walked back to the reference department, and then into the children's room at the back, past another lobby, where a graceful curving stairway led down to an area with an auditorium where we used to give piano recitals.
After I was grown the city closed down the front entrance (disability laws, I guess, because of the stairs), and built an extension with a basic glass-door entrance back on the side. They also took out the lovely curving staircase, put in an ugly closed-off one, got rid of the auditorium-with-piano, and put the children's room downstairs. Oddly, they did not install an elevator.
Years later they tore down the building and put up an ugly, barely functional one that is no roomier than the old one. Why, I have no idea. I just Googled for a photo of the old library but couldn't find one.
I went to library school in a university town that had its public library in an old house downtown. It, too, had creaky floors! The building may still be there (historical home), but the library now is huge and modern (but the old one had atmosphere).