A genetic algorithm to optimize consistency ratio in AHP method for energy performance assessment of residential buildings—Application of top-down and bottom-up approaches in Algerian case study

Abstract In this paper, a methodology for assessing the energy performance of residential buildings in the Algerian context using performance-based approach is performed. This proposed methodology is based on two approaches: top-down and bottom up. The first one is descriptive down to facilitate the identification of pertinent performance indicators “PIs” related to the energy performance quality of residential buildings. The second is a bottom-up approach based on a multi-criteria aggregation using weighted sum method. A coupled method, based on Analytic Hierarchy Process “AHP” and genetic algorithms “GA” method, was used to calculate the weights of selected PIs. This approach is based on the single-objective optimization of the decision matrix (or of the consistency ratio). Application of the developed approach on real case studies of residential buildings in the Algerian context was achieved. The obtained results, based on local measurements, are very interesting and underline the reliability of this approach. The low energy efficiency of Algerian residential buildings was confirmed in the majority of studied cases. The proposed optimization of the AHP method using GA reported very satisfactory results (improvement of the weighting procedure in particular) and led to a better estimation of the energy performance level of residential buildings in Algeria.