Building Carbon Estimator (BCE) : a building specific carbon footprint calculator

Abstract

A building's environmental impact throughout its lifecycle is often assessed in terms of CO2 emissions, also referred to as carbon footprint. Carbon footprint is commonly defined as the total amount of greenhouse gases produced directly or indirectly as a result of an activity and has become the standard for measuring the environmental impact of activities in various sectors from manufacturing, energy, transportation to construction. In building construction, carbon footprint incorporates the embodied energy of constituent materials and systems, energy consumed in installation activities, operation, as well as disposal at the end of the building's service life. In this thesis, we compare five carbon footprint calculators used for building construction. When applied to a simple case study, these tools yielded different values of carbon footprint equivalent, which hinders the in-depth evaluation and validation of the estimates. In an effort to improve the accuracy of carbon footprint calculations, this thesis also presents a calculator that estimates the total carbon footprint of construction buildings while taking into consideration project characteristics (e.g., size, location, material choices). The calculator, which is called Building Carbon Estimator (BCE), relies on data collected from construction materials suppliers and covers the various phases of a construction project. The process is illustrated through a real-world case study and highlights activities with high carbon emissions (embodied, transportation, or operational). A sensitivity analysis is carried out, with emphasis on parameters related to materials' origin and building envelope design.