We have a large back yard and I have always wanted a private office space were I can work. The latest idea is to build a standard office that is 10X10 but you can get a pretty decent offer for a shipping container at about $1500 dollars which if you think about it its a pretty good deal as the container is a sound structure that will last for a long time.
The biggest issue i have found is moving the container to the back yard. Their is a alley way in the back were I can have a crane move the container although the cost to do this was about $4500 dollars, wow that is too much. This may be the deciding factor between a small ready built office or going for a container.
In any case Ben Uyeda has setup a series where we is describing how to build a container home. You can find all the info in the link below
I am planing to use these videos as reference if I decide to go the container route. As you can see one big issue of building anything in California is permits. In this first episode Ben describes the process of getting permits. He bought 10 acres of land near Joshua tree for $20k but the permits alone cost him $25k more, wow maybe in his case it would have been better to build somewhere else.
Believe it or not but you can find options on Amazon to buy a tiny house or office shed that include free shipping. Price is only $46k, although I am sure no one has bought it yet although it has some pretty hilarious reviews.
I will keep you updated on which way we decide to go, and post pictures of the constructions process.