The book is based off of LuSid's design, and yes it doesn't have a back. A friend of mine built a cabinet with that design, and it has no back either. However, when it's turned to a wall or corner, it's not noticeable there isn't one there. You certainly could add a door on the back. For some people there is no need for that. For others, it's possible to add one for "authenticness", "security from the kids", or whatever.