The empty space under the stairs can be useful. You can store things there, this is the most common use. However, there are many other under-stair ideas you

A Luxurious Lounge Area Under Stairs offers staircase storage under stairs that doubles as a cozy retreat. With plush seating, soft lighting, and stylish decor, it’s perfect for relaxing or socializing. This high-end look is easy to achieve with a few decor touches. Discover more lounge area ideas here.