Developing a fuzzy analytic hierarchical process model for building energy conservation assessment

The building sector is responsible for one-third of global final energy consumption. The object of building conservation assessment is to establish and limit the upper boundary for energy consumption in buildings and to promote the utilization of renewable energy and new energy technologies and products. In this paper, a methodology based on fuzzy analytic hierarchy process (FAHP) is proposed for building energy conservation assessment. Within the proposed model, seven factors (building structure, wall, roof, door and window, heating and air conditioning, equipment, and energy) and 22 sub-factors are defined. In the assessment, a decision group is established and members in the decision group are required to provide linguistic variables on the basis of their knowledge and expertise for each sub-factor at the bottom level. Then the decision group is asked to compare the elements at a given level on a pair-wise basis by triangular fuzzy number, then fuzzy pair-wise comparison matrixes are constructed to determine the weights of the factors and sub-factors. The membership degrees on each sub-factor and factor are calculated based on the assessment results. The fuzzy synthesis assessment matrix and the fuzzy synthesis assessment result are then calculated. In order to distinguish the energy conservation degree, the building energy conservation star system is established and the building energy conservation star of the building is obtained according to the assessment results. Then an example is used to illustrate the proposed approach. The results demonstrate the engineering practicability and effectiveness of this method.