Genetic Optimization for Economic Feasibility of Refurbishment in Buildings

This paper investigates the possibility to enhance the thermal characteristics of a building fabric taking into account the economic feasibility in order to avoid useless expensive interventions. The problem consists in realizing an internal insulation system for a single apartment located in Trieste. A genetic optimization has been implemented in order to search a large number of solutions with multiple objects and constraints. EnergyPlus has been used for dynamic building and plant simulation and modeFRONTIER for optimization loop setup. The objectives are the used heating energy consumption and the life cycle refurbishment cost, using a net present value approach. An additional objective has been added in order to guarantee the maximization of the interior useful floor area, which is directly influenced by the internal insulation thickness. Different approaches have been compared, considering actions dealing with opaque surfaces only or considering the replacement of existing windows. The paper demonstrates that an automatic optimization approach can help designers to identify the best suited intervention for building refurbishment.