For a 12x16, all you want is a single room. Maybe a small kitchenette in one corner to cook on (hot plate, mini-fridge, microwave if you wanna get
fancy), a bed that can be used (or convert to) a couch, a couple chairs, maybe a TV antenna somewhere so you can get news and a small generator to
power things.
As for water, you could retrieve a lot of rainfall water by making the roof a shed-type, sloping one way only. Then gutter the water into your rain
barrels. This would be mainly non-potable since the dirt that will get on the roof will be in it, but that would take the load off any potable water
supplies you set up.
As mentioned earlier, if you can recess it into the ground, that will help with heating/cooling, since you will get some geothermal effect. It will
also strengthen it against nature's fury. If you're on top of a cliff, that will be a concern. Use modern technology to tie everything together with
metal ties (tornado ties, hurricane ties, depends on where you live what they're called).
If you do recess it, look at the drainage to be sure the thing doesn't rot away or flood after the first rain. Groundwater can be tricky to
control.
On the subject of rot, if you really want it to last, look into building it with something like cypress. It's pricey in some areas, but where it
grows it is as cheap as pine. It will not rot, period, especially if you treat it initially. I'm actually thinking of borrowing a flatbed and paying
the fuel to go get a trailer load for myself.
Of course, if you want something that will last without turning yourself into Grizzly Adams, you'll have to either build it yourself (including
getting all the needed tools) or pay a contractor to do at least part of the job. You will need concrete for a strong foundation, so you'll have to
have access for a truck or buy a mixer and spend a few back-breaking days pouring it yourself. Either way, it'll be expensive and hard work.
That's not to discourage you, just want you to know what you're getting into. Sounds like a great project, and I wish you well on it.
Edit: I thought of some more.
You could try going with post and beam construction, using posts (around here we use red cedar for durability) and beams across them, sort of like a
barn would be built. Dig those holes deep, 2-3 foot at least to make it strong enough, tamp them tight, and use
big posts. If you're lucky,
you can cut them on site. you can make the beams from large dimension rough-cut pressure treated lumber.
TheRedneck
[edit on 23-6-2008 by TheRedneck]