Building a house is no small feet.  Even a small one. There are thousands of materials, pieces, and tasks involved.  Unless you are a builder or experienced it's intimidating.  But, what containers as perfect modules allow you to do, is simplify the entire process.  Think of a typical 1,000 square foot house.  Try and work through in your head the total length of timber for the framing, square footage of sheathing, number of floor joists required, and ceiling rafters. Can't do it.  Not too many can.  Now think about that 1,000 square foot house made out of shipping containers.  It's 3 forty foot containers.  By reducing the house into 3 base component pieces (modules), it's much easier to understand, design, and build.