Reducing the Life Cycle Environmental Impact of Buildings Following a Simulation-Optimization Approach

Abstract

Identifying building designs with minimum cost and environmental impact is a fundamental topic in the transition towards a more sustainable residential sector. Energy efficiency strategies can reduce energy consumption in buildings, thereby decreasing their environmental impact without compromising comfort. Among these energy efficiency strategies, building insulation is particularly appealing due to its low cost and high potential energy savings. This study presents a systematic methodology for determining the optimal insulation thickness of the external surfaces of a building. Our approach, based on multi-objective optimization, minimizes simultaneously the cost and environmental impact associated with both the construction materials and the energy consumed over the operational phase of the building. The thermal loads are calculated by EnergyPlus, a building energy simulation program widely used by architects and engineers. The environmental impact is quantified following the life cycle assessment methodology and explicitly incorporated into the multi-objective model as an additional objective to be optimized along with the cost. We applied our approach to a case study of a house-like cubicle, for which four potential European locations with different climate conditions and electricity prices were considered. Solutions that reduce around 40 % both, the cost and environmental impact, with respect to a cubicle without insulation were identified. Our systematic method is intended to assist decision-makers in the design of more sustainable buildings.