A performance-based approach for coupling cradle-to-use LCA with operational energy simulation for Calcium Silicate and Clay Bricks in masonry buildings

Abstract

A performance-based approach for assessing the environmental impact of masonry buildings is proposed. This new method combines Life Cycle Assessment and operational energy (OE) simulations to compare the cradle-to-use environmental performance of a reference building composed of single core masonry walls made of Calcium Silicate Bricks (CSB) and Clay Bricks in Germany over a period of 50 years. To achieve this, a detailed process-based life cycle inventory and a methodology that combines material embodied footprints with operational energy simulations is developed, while also considering the vertical limit state for loading the walls. The study also considers the impact of future electricity mixes, the efficiency of heating, ventilation and air conditioning systems and the effect of lime-based construction materials carbonation on the optimal insulation thickness for a reference building. Results show that the OE consumption is the dominant phase in the overall environmental performance of current masonry buildings. Moreover, the balance between the material embodied footprint (MEF) and the OE at use phase, strongly depends on the impact category under study. If fully renewable-based electricity supply and highly efficient heat pumps are implemented, the role of MEF plays a decisive role, particularly in terms of climate change and resource availability damage areas. Moreover, the role of carbonation in CSB may contribute to up to 20% of carbon footprint reduction at a building scale.