Architecture has always had to relate to climatic conditions while providing shelter from the sun, the rain, the winds or the cold. This is a main purpose of buildings: To establish an indoor climate different from the outdoor. In the Nordic countries fuels for heating buildings has been a vital necessity almost as basic as food and water, and lack of wood has caused illness and migration - scarcity of energy is not a new topic either [Kjærgaard]. The new aspects are that human civilization is in danger of causing severe global climate changes, secondly that we can foresee using up the global non-renewable reserves of oil, gas and uranium, both aspects capable of pulling the carpet under human civilization itself as we know it. The huge energy consumption especially in the northern hemisphere is closely linked to industrialization, and the response from those aware of energy and climate problems has in some cases been to search for traditional and pre-industrialized ways of building and settlement. The idea of this theme number is not to flee from modern life and approaches, but instead to face modern conditions relevant in achieving sustainable urban development and sustainable architecture, the only truly modern architecture that exists.