Because we have the ability to make our bi-fold or sliding doors wall to wall and floor to ceiling. You can create a closet anywhere. Take a look at the photographs and you can see how easy is is to install a Custom Door and Mirror bifold or closet slider door.
Look how a walk-in closet is created from a completely open room. First measure and build any shelves for your closet opening. Then measure from floor to ceiling and wall to wall at the depth(distance from the wall) you need and there you have it. That's your finished opening. Then decide what type of closet door you want. Mirror closet doors or bifold closet doors with or without mirrors or even solid flush or routed doors for versatility in finishing options.
Then just follow the instructions in your new CDM door and you have created a brand new closet.