Exploration of life cycle data calculation: Lessons from a Passivhaus case study

Executing a life cycle carbon analysis on a building has two components to consider: the Embodied Carbon (EC) and In-use Carbon, the sum of these forms 'the building carbon budget'. The in-use can be obtained through regulatory tools such as the Standard Assessment Procedure (SAP) in the UK. Embodied carbon has a loose framework with little guidance on a standardised methodology. This paper explores embodied carbon analysis using building components to enhance the understanding of the sensitivity and categorisation of measurements to propose a methodology. The exploration of differing methods on a Passivhaus case study was undertaken with the use of global warming potential identified as the correct unit of measurement. Different methods of estimating quantities and datasets used for an EC calculation are discussed. Results highlight a variation in carbon emissions for certain common building materials between the method used in the Environmental Performance Declarations (EPD) compared to current databases such as Inventory of Carbon and Energy (ICE) using Cradle to Gate data. Designers prefer simple embodied carbon calculation methods. This paper identifies a calculation method giving an acceptable accuracy with the least amount of input data required to implement regulatory standardisation within the industry.