The main problem with prefab is transportation costs. It is not surprising that the homes were setup in Berkeley, which is near a port, since sending goods by s

The main problem with prefab is transportation costs. It is not surprising that the homes were setup in Berkeley, which is near a port, since sending goods by sea is like 50-100 times cheaper per distance traveled than by roads. Plus sea travel cost comes mostly from weight, not size, so transporting bulky items with mostly air by volume is ok. But for more inland travel transportation cost for pre-built modules becomes very problematic. It is much cheaper to bring dense raw materials. But then of course the issue is high building cost and 3D printing tries to address that.