The World Inside (TWI) somehow reminds me of another architecture-based science fiction: the cyberpunk manga by Tsutomu Nihei called Blame! Both are really good in using space to create an alien atmosphere and setting. There is a sense of largeness in both that paradoxically engenders claustrophobia. I have finished the manga series Blame! and I am writing this while I am half-way through TWI. Whereas TWI teems with people in its corridors and rooms, the world Killy inhabits is a vast and mostly empty space. But enough with the comparison.

There's a lot of sex in TWI. It was written in the 60s and so we have to consider the social setting of the novel's writing. There's also drugs and rock and roll in the novel, also things that are very 60s.

The prose is good. The characters are well-constructed. The world is revealed slowly and methodically. Overall, this is a solid work of science fiction.

EDIT:

I have just recently finished the book. Wow. There are several scenes that would require a little openmindedness. Is it a dystopia? Part of the appeal is that after reading so much of the lives of the people in the urbmon and how it is the only world that they know, the line blurs a bit. Has that whole 'Plato's Allegory of the Cave' vibe to it. I highly recommend this novel.