Here are a few good websites for some information on Eco friendly houses.
NZ Eco. House: This is a few aspects of Eco. homes.
Eco. Bob: This showcases some Eco. homes that are for sale but have pictures and aspect lists ETC.
Eco. Home: A story of some people building their own Eco. home.
Eco. Plan: A plan of an Eco. House
Eco. houses usually consist of solar power so power that is powered by the suns rays on a solar panel. You can also make Eco. friendly mud bricks which are made of mud and clay made into a brick shape then left to dry so you can from walls with it. The special thing about mud bricks is that you can carve your name and leave a special mark. You cannot always get Eco. Friendly things but it is best to go with the most Eco. friendly option so even if it is not entirely good for the environment you are still helping the environment.