Ecological buildings cannot be categorised under one heading; they sit along a spectrum. At one end there is Green, and at the other Autonomous. By being selective it is relatively easy to build Green. To be Autonomous takes technological ingenuity. Along this spectrum sit all manner of building technologies, the Segal Method, Straw Bale, Rammed Earth, Adobe, Earth Sheltered, Timber Frame to name but a few. Each demands a different commitment and understanding.