Here is an IDEA, shipping container housing, infinatley modular and to boot much cheaper, by almost half to 3 quarters the cost....i have been doing designs of these type of home for fun and you know what, i love them, not to mention the fact if i wanted i could pack em up and put them anywhere else, its not that we should seriously consider the change to the environment of San fran, for which i am sure there is merit in some cases, but why not make a location that can conform to your needs and then build how you want to build, live how you want to live, in a place that welcomes you... food for thought