Optimal Trade-Offs between Social Quality of Life and Life-Cycle Cost in Housing Units

The social quality of life (SQOL) for single-family housing residents can be improved by enhancing their thermal comfort, indoor lighting quality, indoor air quality, and locating the housing unit in high-quality and safe neighborhoods. Accomplishing these SQOL improvements often leads to an increase in the life-cycle cost (LCC) of the housing unit. This paper presents a multiobjective optimization model that is capable of generating optimal trade-offs between the two conflicting objectives of maximizing the SQOL for single-family housing residents and minimizing the LCC of single-family housing units. The model is designed to maximize the SQOL for housing residents by improving their thermal comfort, indoor lighting quality, indoor air quality, and neighborhood quality. The model is also designed to minimize the LCC of housing units by minimizing the initial housing unit cost as well as its annual energy, utility, and maintenance costs. The model is developed in three main stages that focus on (1)identifying relevant criteria and metrics to measure the performance of these two optimization objectives; (2)modeling all decision variables, objective functions, and constraints; and (3)implementing a multiobjective genetic algorithm model to evaluate its performance. An application example of a housing unit is analyzed to illustrate the use of the developed model and demonstrate its capabilities in identifying optimal configurations of single-family housing design and construction decisions.