It has economical and social value to build energy-saving architectures. Foamed concrete is commonly used as non-load bearing structure to save energy of buildings. With reinforcement of fiber foamed concrete can be used as load bearing structure to build architectures. The load bearing structure of fiber reinforced foamed has ability of self thermal insulation to get the aim of energy-saving. In the paper the excellence and disadvantage of foamed concrete is summarized. Methods are given to build the energy-saving architecture with self thermal insulation structure of fiber reinforced foamed concrete in new formwork. The building technology will be applied in new countryside construction in China.