Retrofitting of Housing Blocks Minimizing space heating and cost using combinatorial optimization modelling and algorithms

Abstract

This report details an approach toward finding Pareto optimal solutions to the problem of retrofitting buildings by modelling it as an integer linear optimization problem. The report discusses some background to its importance, e.g., that many buildings do not currently meet the standards set by the European Union for energy efficiency. A current prognosis shows that these standards will not be met in due time, and as such the DREEAM project aims to improve the work being done on retrofitting buildings. The optimization tool DreeamTool, currently being developed within DREEAM, uses a stochastic algorithm, NSGA-II. In the report it is shown how a method based on integer linear programming with multiple objective functions performs, as opposed to the current method. It is shown that the mathematical model and solution approach finds Pareto optimal solutions in a computation time that is considerably shorter than that used by NSGA-II for finding an approximation of the Pareto front.