So the factors of what you want is really going to determine what you build.

I like the idea of being less dependent on the grid and taking advantage of your immediate environment to heat/cool a house and design with respect to moisture, etc. will be needed. But I also like creature comforts and love living in a large, spacious environment with all the bells and whistles. I don't think the two are mutually exclusive. Earthship homes or some variant of them would need to meet building codes, but do they exceed them. My only concern is if a tornado, ice storm, or something like that comes through are they better suited than conventional construction? Again...so many factors to consider... Environmental, Security, Space...and at the end of the day...livability. Is is the style you want? We each have different tastes and wants in a home.

Some interesting and good points so far.

What about building into the ground?

Could you build into a hill with materials that would last for generations, while dealing with things like mold, and critters etc...?

Certainly there are lots of examples of modern reinforced concrete and ancient stone buildings built banked into hillsides , and those carved into hillsides in appropriate drier climates and even places like Chinas underground city built into the ground itself. Materials and structural design all need to be appropriate to the individual siting and climate. No one thing will be appropriate for all. I would love to hear ideas outside what we consider conventional , I see things in New Zealand I find unconventinal here like a lot more use of bifolding doors and windows and very few bug screens . Here on the Canadian west coast we have coveted vaulted ceilings that are nice for dissipating heat in warmer climates are more expensive to heat here that do not make sense to me , even with anticipating climate change : ) I hear talk of passive solar heating from south windows here but thermal heat sinking into designed mass is rarely brought up. What passes for convention seems to have a lot of faults that could be improved upon.

I thought i had sent a reply to perfesser's points about moisture,...but somehow it got lost.

While i will likely have the SIPS mobile cabin as a startup refuge,. my eventual earthbound design will hopefully be utilizing the "annualized solar gain" methodology. I've kept this intent since first reading about it around 8-10 yrs ago. ....by an architect in colorado....and have noticed some of the principles have since been incorporated in other experimental designs.
This requires that the drainage is correct on the building site.

As i recall, the idea is to create a mantle of rigid closed cell foamboard around a pre- graded/sloped perimeter of the dwelling , with vapour barrier on top to bridge the joints(,deflecting heat-draining rain) then sand and topsoil/grasses. Essentially this can be funneling geothermal heat towards the unbroken-insulated wall of the dwelling through
coarse aggregate under the footings.....and/or with optional passive solar units further out doing the same via Big-O under the foam as well.
Other Big-O pipe is routed thru cooling earth only, for air exchange and convection.
This presupposes a sufficient sloping around the house to situate the solarboxes to assure unhindered heat rise .
Apparently the experimenter registered an average annual gain in temp. of 1-2degrees.in the first few years .
This is the best example of consistent "free heat" which i'v e come across. In effect, this setup would tend to dry the strata below more than any moisture-wicking from beyond the perimeter
There are more details to address like monitoring the induced convection, and fresh air, etc.
Naturally the first thing to determine is that there is no radon seeping up.
The floor could be wood planks on aggregate, and some isolated cement/tiled pads or natural rock slabs ...placed as heat sinks by windows.
I think that even if the sun were to become invisible for some periods of time, the heat of the earth mantle would diminish comparatively slowly.
I believe he had a tiny stove as backup and for hot water. Even the water would be preheated in the aggregate and/or in the heat sink coupled with the stove.
This was before the now-popular rocket stove tech.

I am thinking about lots of ideas, trying to get some ideas that are economical, efficient , aesthetically and ergonomically pleasing while being more environmentally friendly and fitting into a sustainable permaculture type system .
One thing I have sort of opened my mind to is the idea of building a home in units, even incorporating some but not all shipping containers , so as not to incur debt, design to add on as priorities can be accomodated ? Keeping in mind solar aspect, earth berming , using slope for permaculture applications , water catchment and cistern storage, maybe glasshouse units being bridgable to the housing unit ? And I am not sure that I need all the conventional allocated rooms , for instance I am thinking whatever space I use for a bedroom at night, can serve as living space during the day whether that is a murphy type bed or a bed platform that tucks under something else or a platform raised and lowered from the ceiling and some beds may well be hammocks. I just eat up those ideas about sliding walls and transformable furniture especally if we could do it ourselves affordably with really great design .
I'd like to utilize what people think of as bedrooms for additional things . My living space can flow inside and out accordingly with weather and climate temperature so being able to expand to the outdoors seasonally at least needs to be thought of but keeping with the idea as I age I may appreciate the interior comforts more. I am not altogether sure people need conventional bathrooms either, I think on average I might spend 15 minutes in one daily so for sure a biffy set up is on my list , but can we adapt a living area where we can wash and brush our teeth, maybe even shower and such in a "wet" area that we can also use for food preparation ? Furnishings too seem to be open for adaptation. I like to sit on exercise balls rather than have so many chairs and you can keep move them so easily , that having the amount blown up to fit the occupants is easily added to with a a few extras stored away and a foot pump works in minutes , except they don't last 50 years like a chair can. So the idea of having a table has for me sort of turned to having a coffee table that can be raised and expanded out with hinged or insertable leaves if you will, to accomodate dining and be shifted indoors or out with ease, maybe on locking castors ? I sort of have some idea that if an office chair can be made that way, so can a coffee table that can further be transformed to dining table , bed platform or desktop ? I just sort of think we can take traditional function and upscale some ideas , to be multifunction or make slightly smaller spaces more versatile so I pack more efficiency in , better utilization and still come out with a cleaner looking design and good flow without sacrificing comfort and do it all with more recycled and creatively repurposed materials?
Can your roof watercatchment be optionally solar or woodstove heated or on demand unit heated and utilized to a loft level shower and bath that the grey water is gravity fed optionally for water the garden or flushing the toilet and toilet waste going to a downhill biodigester to produce gas and fertilizer ?
I am thinking doors to rooms or storage cabinets could have sliding fronts on tracks and have decor so they look like differing design textures on walls and sort of seamlessly fit together , also this with more pocket doors and less swinging interior doors that again the decor makes them look like wall for a cleaner look ? I guess I think about keeping some traditional conventional aspects but also having some different things adding to the function so you do not end up with a standard house with three bedrooms and two bathrooms with living room and dining room and an ofice den and yet still have it function as one . It might boggle the brain of people new to it but hopefully for its inhabitants its design fits perfectly like a kid leather glove . Now to find ways to make it so.

I been watching shows on cargo container buildings. http://www.youtube.com/results?search_query=cargo+container+cabin&sm=1
They seem to be a good idea, if you can get them cheap enough. You would need some welding expertize.