Lester Walker's 1981 classic American Shelter, (still in print!)
American Shelter
I do not mean this as any criticism of Blu Homes; I think they deserve praise. If modern prefab is going to catch on it has to be affordable, and the way to do that is to maximize the efficiency. There is no simpler or more efficient prefab than banging two long thin boxes with shed roofs together.
Toss in Blu Homes' folding system that dramatically reduces the amount of air that they are dragging across the country and eliminates all the special, expensive transport permits and escorts, and you have really squeezed out a lot of cost.
More on the Blu Homes balance; see Preston's take on it at Jetson Green
