Houzz: If you don’t have an entire room available for a home office, consider the space under the stairs as a great alternative. The built-in desk and bookshelves of this modern office in Austin, Texas, make for a stylish workspace.
Staircase storage - Simple version for under stairs storage. This would totally work if we gutted the basement as it is now. (Plus, no more dark crawling under the stairs to get at my christmas decorations!
Look for dead space under stairs and in deep walls. There is often room under a staircase for a small closet, powder room, or even built-in shelves for cataloging books, files and other knickknacks that create clutter