I have a recurrent happy dream, and it looks something like like this picture on the RHS. What a delightful idea, a staircase that doubles as a bookcase, leading up to a reading room! The only change I would make to this design would be to arrange for a couple of cushions on some corners of this stair/bookcase, so that, if you happen upon a book you wish to investigate further, you could just browse then and there in comfort.
I have a modest collection of about 300 books now (not counting academic volumes at my office), but have ambitions of some day owning 10 times more. Sadly, homes in the UK are not cut out for such large collections. Given the astronomical house prices, space comes at a hefty premium, and it is unrealistic to harbour ambitions of storing and displaying large collections. That will have to wait for later, much later - retirement! Bee and I have idly spoken of building our dream place in Khon Kaen, her hometown. Projects like these would be much more viable there, where you can make homes to order without parting with an arm and a leg. Someday!