Evaluation of building energy efficiency based on unascertained measure method

Using unascertained measure method, this paper established evaluation model of building energy efficiency based on seven influencing indexes, including the U-value of external wall, the index of thermal inertia of external wall, the U-value of roof, the index of thermal inertia of roof, the U-value of window, the shading coefficient of window and the visible transmittance of window. Application study of this method was carried out. The results show that the evaluations based on this method are in good agreement with the building energy simulation software´s outputs. As a conclusion, this paper provides a new and effective method for the evaluation of building energy efficiency, and it can avoid arbitrary in the past purely subjective and emotional evaluation.