Prefab shower stalls can be either faultless single piece unit or a composition of many units such as solid side panels and shower pan and the deciding factor between the two is whether you have a large door or not! Strange and a little surprising! But, don’t be surprised. If you opt for a single unit Prefab shower stalls, you have to get it through the doors of your home and hence it is the deciding factor else there is no such difference between the two. All you need to install the prefab shower stalls is budget and space. That’s it!