I am going to help him assemble whatever he eventually settles on, and I offered to do the research because I have a computer.
I have been searching and searching and like with many subjects the hours I've spent haven't been very friutful, so I found this site and decided to ask for help.
Here are the things he's looking for:
Inexpensive but good - he's not interested in paying for anything but the actual quality of the home, no brand names will impress, no fancy ornamentation will be considered worth the extra cost. Off the top of his head he would LIKE to pay no more than 40-50K total, but that's not cast in stone and there are a great many variables, so he's unable to quote a price per square foot. He knows that price may be totally unrealistic but he's trying for that.
Although he's off the grid he would like the house to be code or better. He would have to pay roughly 10K to hook up to PG&E and he probably never will unless he ultimately generates so much power of his own that the power company would have to buy back that it would easily pay for itself. Not likely. However, going with code or better all around is what he wants to do.
He has a generator that's 110/220 and will likely install some propane appliances and put in a tank, but as this is new construction it makes sense to look at building in energy efficiency/harnessing/storage. It's likely cheaper to do it that way than to retrofit later one. At least he wants to consider as many options as he can.
I've found a number of prefab sites and so far have only found one that I think he'd be interested in. It's the Unit One on the Shelter-Kit site. That is inexpensive and simple and has the advantage of being designed in such a way that a person can add on very easily if he wishes to later. It doesn't have any special energy-efficiency characteristics, but he could add a trombe wall or photovoltaic panels, etc. It's just preferable to find something that is designed with these things in mind.
I would really appreciate any suggestions of sites or search terms that might enable me to find more options. It's also probably a very good idea to figure out a pretty firm cost per square foot. That would make inquiries more simple, but currently we have to think of things like:
Will just the two of us (both small people, though experienced at construction) be able to install it or will more people have to be hired?
Will thousands and thousands have to be spent on energy-related components in addition to the house, and if so how much cost and trouble will the retrofit be? I know that there are calculations people use for cost per KW or something like that, but I don't know what they are or whether that cost includes everything or just the actual parts and labor.
Shipping could also add a huge mount to the price, so it makes sense to try to find a supplier who is as close as possible.
We live in Northern California in the very low Sierra Foothills and there's a great deal of sun here and warm weather. Although there's generally a breeze it's not really considered optimal for wind power, so solar would be the most sensible approach of the two.
There is a great deal of granite here so digging foundations is impossible and of course berm houses therefore similarly unthinkable (we have to use almost all raised beds just to grow food!).
Thanks in advance for any help.