A BIM-based Framework for Quantifying Embodied Emissions from MEP Systems in Building Life Cycle Assessments

Abstract

Embodied emissions from Mechanical, Electrical, and Plumbing systems (MEP) in buildings contribute substantially to the carbon footprint of buildings. Because of lack of standardized methods, reliable data, and environmental product declarations (EPD), MEP systems have typically been excluded from Life Cycle Assessments (LCAs). With increasing emission reduction efforts for other building components, the share of embodied emissions for MEP will rise if not focused on. This research fills the gap by introducing a comprehensive framework for quantifying embodied emissions for Mechanical and plumbing systems (MP). Our approach includes three main components: a BIM based embodied emissions calculation methodology, an EPD database, and guidelines for estimating emissions in data gaps. Seamless integration into the building information model (BIM) tool Revit, allows MEP designers to access real-time emissions data and engage in iterative design for reduced carbon footprint. Testing of the framework on a building in the design-stage indicates that emissions from replacement of components can constitute up to 50% of total material emissions for MP during the calculation period, that the emissions from MP can be in the order of 8-20 % of the total emissions from material use in a new office building and that ventilation, heating and fire suppression constitute the largest contribution to the total. Optimization of MP-solutions appears to offer substantial emission reduction.