The front door is used to slide in the kiln shelf or anneal beads. When determining where you will place your kiln, you need to keep in mind that you'll need room so that you can slide the kiln shelf into the kiln. You also want to be able to open any other doors like the one on the top in this model or a side door like some other kilns have. So, basically, you want enough space around the kiln so that you can easily access it.
The primarily issues to keep in mind when setting up any work area is safety and accessibility. Glass is a wonderful art medium and has lots of possibilities when it comes to jewelry designing. Even if you don't have a fancy professional set up, you can create your own work space at home and still enjoy working with glass.