This paper proposes an improved multi-objective optimization model for building energy retrofitting. Apart from the extensively investigated objectives: minimizing the overall energy consumption and reducing the life cycle cost, another objective is involved: the overall user satisfaction during operation. The newly introduced objective reflects the fact that upon the deterioration of appliances, the user satisfaction decreases accordingly, and this must be reversed via facility maintenance. A multi-objective optimization model with all three objectives is established to support the building energy retrofitting decision making. A recently proposed many-objective optimization algorithm, NSGA-III, is employed as the numerical solver. A simulation test is conducted and the relationship between objectives are investigated.
Keywords Energy efficiency retrofits, Multi-objective optimization, User’s satisfaction