Making structures for my next showcase/game

Golly gosh, I’ve finished two buildings for my next showcase/game for today. Welp, I would show you what I’ve made so here’s the first one:

And its interior:

Also the second one:

Top view:

Bottom view:

And also its interior:

Give me a feedback/opinion on this build and what I can do to improve it or make it refined. Any suggestive tweaks would be appreciated.