Mini storage floor plan layouts. the mini storage building layouts below demonstrate some of the different storage unit sizes that are available and can be custom configured for your buliding. click on building illustrations below to enlarge the images. This article is devoted to helping you plan your own mini-storage complex, featuring advice on location, lot-size, mix, floor-plans, and more! it is also designed to prepare you to communicate your requirements, when you get in contact with your metal building systems manufacturer.. Check out our monthly specials for low prices on mini storage buildings and self storage units. our prefab storage building kits are designed to fit your needs..