We needed beds for 3 children, one of which is 14 months old, in a small bedroom and with the simple bunk bed plan to start with I came up with this. The kids love it, although it took the 14 month old a few tries before she accepted the change from her regular crib in another room to this crib/bed and sharing a room with her siblings. Now it's all good!
The beds can also be used separately. The top bunk and the middle bunk will stand 30 inches off the floor when used as separate beds, so like loft beds with storage space underneath for a dresser, reading nook, toys, etc. All side safety rails can be removed for unstacked beds as I finished them all separate from the beds. The bottom "crib" bed side rails can also be removed for single bed. At this point it would just sit on the floor as a single bed also but I may come up with some sort of feet to get it up off the floor when the time comes. They really wanted this set of bunks to be able to be used separately also. The fold-down portion of the "crib" side rail was designed to give easier access for changing sheets, etc. for the "crib". This "crib" bed also uses a regular twin mattress.