The empty space under the stairs can be used for many different purposes, you can store things there, create a mini library, a dog house, kitchen pantry, mini bar, or a small closet, etc. There are many other under stair ideas you can opt for, depending upon the type of space you’ve there. But the idea that best fits the area under the stairs and looks great as well is creating an Indoor Garden Under Stairs, the only requirement it has is some bright indirect light or you can also use some artificial lights.