Today we are going to discuss the options for a Foundation. As previously stated the foundation would be done with SonoTubes and rebar reinforced pier footings. This is most certainly the way to go for our needs. In comparison to what Alan did, he used cinder blocks. Example in picture comes from http://www.thearkhaus.com/ This is the most inexpensive and the fastest method of creating a foundation for a container. Which is fine, there is nothing wrong with this idea. If the container were to shift/move, it would only take a small amount of effort to right it back to level and shim the corners. This also makes for a very easy way to move the container if you sold it, or needed to take it to a new location. The pier footings would not come out of the ground or be moved without a lot of work. Plus the containers should be welded to the weld plates. This will make moving/removal or whatever more difficult. But for our sake, we are needing a very permanent solution and mounting on welding plates is the best idea for our new home. Here is a shot also of another container from http://www.geeksville.com/~kathy/ktainer.html and they used pier footings in a very similar fashion to what we are expecting to use.
Other than these options, we have only considered a monoslab foundation from concrete. Which is a massive concrete slab that works well in many ways. It gives a solid surface to create you building on, it has terrific thermal properties that heat in the winter and cool in the summer. However, the drawbacks are that this type of "slab on grade" is expensive, time & work intensive, and can be very difficult to fix or change out pipes & plumbing should there be a problem in the future. Containers also need AIRFLOW under the bottoms so that moisture does not build up. This would cause rust and the eventual degredation of the container itself.
So at this time we have ruled out that idea. If there are any options or things that have been left out, by all means include that in the comments, that is why we are here brainstorming!