16/ A Storage Room
It's not a bad idea to use your attic as a storage space. With all empty space, you can easily store all of those unused furniture and belongings for when your children move out. Furthermore, if you're looking for another place to live or didn't manage to get rid of the items you have.
Whatever it is, you can use your attic as storage. Nevertheless, make sure to keep it clean and tidy so you know what's to find up there and where everything is. At one point, you might want to spend a few moments up there to relax and just chill.