You can buy new and second hand containers from many outlets.

 

New is best - The Buying Strategy 

The main reason for this is rust! as is the name shipping container.  Most containers spend a lot of time at sea on large ships and through this they are exposed to the worst possible conditions, such as heavy storms and rough seas. This can cause dents, scratches and the salt air is the best ingredients for major rust problems, deep within the structure of the container. 

Second hand containers may be only a couple of thousand less than a brand new one, so the costs of repair and rust proofing will far out way the costs of a new container.

 

In my opinion, 40 ft. is best. 

Of course, it does come down to your budget and size requirements, however, the cost difference between a 20 ft. and 40 ft. container is minor compared to building a full-size home. 

​

20 Foot Container 

A 20 ft. container is a bit less in the outlaid cost, however it is a very small area to work with.  The container size is 20 ft. by 7 ft. or 6 meters x 2.1 meters so you can only fit a very small bedroom, tiny bathroom and living room. In fact, the area is so small you are best to have a combination living / bedroom/ kitchenette area with the only separate room to be a small bathroom.  This still works as a small home or flat type but does not give you a lot of space or storage.