30,000 is an incredibly large number of books for one person to have. Assuming that each book is a fairly narrow .75 inches and your shelves have 8 layers vert

30,000 is an incredibly large number of books for one person to have. Assuming that each book is a fairly narrow .75 inches and your shelves have 8 layers vertically, you're going to need 234 linear feet of shelves. Assuming your shelves are 3 feet apart with six inches on each side for the shelves, you need 468 square feet of floor space dedicated exclusively to book shelves. That's roughly equivalent to each person in the US using their entire living space for books. I'm pretty sure worldwide, most people would need more than their entire living space.