Create an Indoor Garden Under Stairs. This can be a unique place to introduce some greenery to your home.
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 can opt for, depending upon the type of space you’ve there. A mini library with bookshelves or a reading nook or a home office, if it’s big enough.
A dog house or playhouse for your kids can be an interesting idea too. And, if your kitchen doesn’t offer a lot of cabinet space and it’s near to that under the stair place, make a kitchen pantry. The Kitchn.com has a remarkable post on it, check it out here. You can make a wine cellar as well by taking inspiration from this post.
If the idea of making a wet bar to entertain your guest interest you–must try that. Besides all these under stair ideas, you can make a closet to store your clothes. A small bathroom, a mudroom can also fit well there. There are plenty of projects with tutorials available on the web to teach you how to do this.