The Development of a Parametric Framework for Embodied Carbon Design

Abstract

The building industry is the largest global contributor to carbon emissions. At the current rate of carbon emissions within this sector, the targets set by the Paris Agreement will not be achieved. Consequently, significant reductions in carbon emissions from the building industry are needed to align with global climate goals.

When discussing the carbon emission of a building two major type of carbon emissions can be distinguished: 1)operational 2)embodied. Operational carbon is all the CO_2 that is emitted during the use of the building and refers to the energy-related carbon emissions. Embodied carbon is all the CO_2 that was emitted to realize the construction of the building.

Historically, sustainable building design has focused on reducing operational carbon. However, as improvement in low-energy buildings continue to decrease operational emissions, the significance of Embodied Carbon has grown. Despite this, Embodied Carbon remains underrepresented in the design process, often addressed reactively at the end of the design, leading to unnecessarily high levels. Embodied Carbon must be integrated in the early design stages to create buildings with a low Embodied Carbon content, improving the sustainability of the building industry.

This master thesis introduces a parametric framework designed to embed Embodied Carbon assessment into the early building design process. Recognizing the uncertainties inherent in early design phases the framework prioritizes delivering ranges of values rather than precise figures, befitting of the dynamic and flexible nature of design exploration. By offering quick, clear results and transparent methodologies, the framework stimulates a multidisciplinary workflows, enabling accessible, efficient, and informed decision-making without requiring specialized expertise.

The framework consists of three tools; 1)Structure Generator Tool: Translates design parameters into structural systems and material quantities without requiring specialized engineering knowledge. 2)Embodied Carbon Material Factor Determination Tool: Converts material quantities into Embodied Carbon values using databases, with the flexibility to include or exclude biogenic carbon storage. 3)Iterator and Data Evaluation Tool: Supports iterative design exploration, comparing design alternatives and facilitating clear visualization and communication of results through tools like DesignExplorer.

The developed framework effectively supports the early design stage by providing actionable insights, enabling designers to quantify the impact of their choices with ease and efficiency. By integrating multidisciplinary variables, default settings, and automated element generation, the framework stimulates a multidisciplinary collaboration without requiring, but allowing the application of, specialist expertise. A range-based approach accounts for uncertainties in Environmental Product Declaration (EPD) selection, while sensitivity analyses helps distinguish robust conclusions from those sensitive to design changes and allowing the converging of the carbon assessment throughout the design process. Although future refinements,such as improved connection design and substructure integration, could enhance accuracy, the framework already delivers reliable estimates for Embodied Carbon assessment. Comparisons of databases show slightly conservative results for the Dutch building industry when using ICE V3.0 instead of NMD. Overall, the framework lays a strong foundation for integrating Embodied Carbon considerations into early design, proving its potential to significantly reduce carbon emissions in building practices.