This is a perfect combo of my two favorite ideas for that space under the stairs leading to the basement. A reading nook AND book storage and shelves . assuming that there is enough space for this there.
This is the perfect place to put a pull out bed. I always look at those beds and think they're impractical because it's too hard to leave all of the open floor space needed for one but I'd happily do it for this library/reading space
Amazing built-in nook with glass lantern providing reading light. Reading nook with gray ikat fabric cushions and pillows as well as white roman shades covering windows. Second landing nook with built-in reading lounge and built-in shelving.
Make a Reading Nook With Shelving on Your Bay Window Seating. Your bay window seating may be small but you can make it look bigger and more functional by adding a reading nook on one wall. via marcusdesigninc.