Low-tech passive solar design concepts and bio-based material solutions for reducing life cycle GHG emissions of buildings – Life cycle assessment of regenerative design strategies (2/2)

In order to achieve the necessary reduction of greenhouse gas (GHG) emissions and decarbonization of building construction and operation, both high- and low-tech building design strategies are promoted. Amongst particularly promising strategies are the deployment of energy efficiency measures, for reducing operational energy use and related impacts, as well as the application of low-carbon, bio-based construction materials, for reducing embodied impacts. In part two of our study on the life cycle assessment (LCA) of regenerative design strategies, LCA is applied to investigate the environmental impacts and reduction potentials of strategies at building level by analyzing two low-tech, passive building concepts – the be2226 building and the N11 SolarHouse – in both their original designs as well as optimized alternatives applying bio-based material solutions. The analysis includes three steps. In a first step the life cycle GHG emissions of the original buildings are assessed, revealing strengths and weaknesses on both operational and embodied GHG emissions. Environmental hotspots are identified across environmental indicators, life cycle stages and building elements. In a second step the case studies are remodeled with bio-based building element alternatives showing substantial embodied GHG emissions reduction potential compared to the original case studies. Finally, the results of all building variants are compared with climate targets for buildings revealing that the N11 building meets established climate targets already in its original version, and that a straw-based material optimization can even enable meeting more ambitious climate targets.