Integrating life cycle assessment into the building design process - a review

The environmental effects associated with buildings are significant, and include considerable contributions towards global greenhouse gas emissions, energy use, and waste generation. Until recently, mitigation efforts have concentrated on improving the operational energy efficiency of buildings, largely ignoring embodied environmental effects. However, focusing solely on increasing energy efficiency can inadvertently cause an rise in embodied effects. It is therefore critical that embodied effects are considered alongside operational effects and are actively integrated into design decisions throughout the building design process. Life cycle assessment (LCA) can be used to achieve this, however, it is often perceived as difficult to incorporate into design workflows, or requiring specialist knowledge. Additionally, it is not always clear how well aligned LCA approaches are with the building design process. To address this gap, this study aims to provide a detailed analysis of LCA approaches, to assess how well they align with building design stages, and to identify key characteristics, including LCA tools and environmental data used to conduct assessments. A review of academic and grey literature is conducted. Three primary approaches are identified for integrating LCA into the building design process: simplified, detailed and incremental LCA. Simplified LCA uses streamlined data inputs and typically targets a specific design stage. Detailed LCA follows a traditional approach with comprehensive user inputs and results. Incremental LCA progressively evolves the assessment based on design requirements and available building data at each design stage. An analysis of each approach is performed, and key user requirements are mapped against the early design, and detailed design stages. Results reveal that no single approach fully satisfies all design requirements. Findings also highlight a lack of incremental LCA approaches and challenges operationalising these techniques. These approaches often rely on complicated methods or tools not suitable for common design workflows, or they are in early development and require additional verification before implementation.