Early Design Stage Building LCA using The LCAbyg Tool: New Strategies For Bridging The Data Gap

There is an increasing demand for Life Cycle Assessment (LCA) as a method for environmental impact and resource assessments of buildings. At early design stages, where major design decisions are made, the potential for improving the environmental performance using LCA is greatest. However, detailed building information is usually not available at this time. This paper presents the recent extension of LCAbyg, the official Danish building LCA-tool, integrating an LCA approach for situations, where building design and material choices are not yet fully determined. The tool assists the user in establishing a complete building inventory by providing a default component library including building services and a guide for estimating quantities. Default components in the library are based on the integrated product database Okobaudat. A convenient generation and comparison of variants improves usability, while a new LCA design guide shall increase the uptake of LCA in larger parts of the building industry. The methodological choices of the approach are laid out and discussed. The presented approach is not limited for use in early stages, but may improve feasibility in building LCA in general as default and estimated values may be refined towards more detail in later stages of the project.