There is no requirement for a closet to be placed in a traditional space in the home. Anywhere where there is a small nook or an unused area in the home that can be turned into a storage facility can be converted into a closet. Naturally you're going to need all the storage you can get in your home, who doesn't? Sometimes you just have to get a little bit creative with where you install them.
Usually, because space is generally an issue, swinging doors are not appropriate for sealing the closet. It may be that you have to turn to other options to find a suitable closet door. Something like a bi-fold or sliding door may be what you are after. Both of these options make great use of the little space that you have and allow you to create storage space where it might otherwise not have existed.
Once the closet doors have been installed all that’s left to do is keep the closet organized and as simple a task as this may sound on the surface, it’s something that many people have real difficulty with. Using a closet organizer or hiring someone to help with the organization might be the wisest ways to solve the problem. There are also some very handy little gadgets that can be used in the closet to maximize the usage of the space.