Here is someone after my own heart. This fellow has two sites both dedicated to creating and sharing Eco housing options.
On his sites you will find many fine Eco Friendly housing options for anywhere in the world and pricing per sqft that enable even people with hardly any money at all able to afford these Eco Houses and buildings. Perhaps you start here, build the Eco Buildings, Earthbag buildings or strawbale infill buildings, then in 10 yrs or so, build a standard style house although why would you want to after living in something so nice and cozy?

Jungle Eco House
The original building can now be used as a guest cottage, writing or craft area or a deluxe and eco friendly barn of sorts. These people offer plans in a lot of different styles and to their great credit, they also offer Free Plans as well. Most of the Shelters can be made from mostly local materials, created on site, or say make the base and walls then put on a prefab truss roof, the combinations are endless here folks.
Here is a great post from the WordPress Earthbag plans blog Water Tower apartments, follow read and let your imagination run wild!
Negative comments directed to me in the past when I say that my future holds me building an alternate house, the comments turn to; it will be dark, dreary, damp, closed in and ugly! Well now most of those comments where by people who live in Sticks and Bricks houses in the city. (sticks and bricks refer to standard 2×4 with brick veneer construction type houses)
My kind of house has thermal mass for the walls and no need for expensive pink insulation, uses the material from the land, no need for expensive huge Carbon footprint to make them. Most of them look very interesting, something that makes you want to smile and go in and see what else there is to see of the place. These are not free houses, or caves or simple dug outs with tarps/sticks and mud over them, however I have slept in all of those and they were mostly comfortable as well, with one exception! Heat the buildings with Rocket Mass Heaters info here, or with Bio Heating via the Jean Pain Method and you will be assured of cozy living with a small Eco and Carbon Footprint, Mother Earth will be most happy if you do so.

You could make this from two Yurts, Earthen Yurts, Earthbag, Strawbale or what ever the mood and materials take you to
Personally I am hoping to build a few different Eco Buildings, one a Mike Oehler’s $50 & Up Underground House Book, another a Yurt, then a modified Canadian Winter Yurt which will be a cross between a round house a pit house a straw bale house with a ceiling and covering of all natural materials with a living green roof.
Take a trip over to his blog and new website, they love to teach, and help out which is abundantly clear in his writings and responses to queries. The trip is more than worth the click.
How about this one, Triple Dome Survival Shelter

Survivalists take not of the Triple dome Survival Shelter
The preceding info pictures and plans are from;
Earthbag House Plans
Natural Building Blog
all pages and writings copyright @ WildernessReturn

Very interesting ! Thanks for the links – I’m going to forward them to my sons since they are planning on building a small eco house.
BTW, I noticed you’ve started to add “all pages and writings copyright @ WildernessReturn” – is this because you’ve had trouble with people ‘stealing’ your stuff? Or what? Thanks
Hmm..
computer ate my response! Glad to help out with the Eco Housing it is a topic that is near and dear to me.
With recent copyright changes you do not have to copyright or even say it is copyright, but it does help. When I first started there were two trolls from a forum, one was a stalker (I am so cute! ) and the other was stealing content, both issues seem to be fixed, but it helps you know.
Thanks WildernessReturn!
Tons of info over at the Permies.com forum as well on alternate building and materials!
http://www.permies.com/forums/c/6/