The environmental impact of building materials, expressed as embodied carbon (EC) or, in the Dutch context, through the MilieuPrestatie Gebouwen (MPG) indicator, is increasingly governed by regulatory standards and sustainability objectives. However, current assessment tools for measuring embodied carbon are typically used as late-stage compliance checks, rather than being integrated into the iterative design process of a new project. Moreover, publicly accessible data on whole-building environmental impact is scarce, limiting the ability to benchmark and contextualize new designs.
This research proposes a computational tool that facilitates early-stage environmental impact assessment of building materials, integrating three calculation methodologies: Embodied Carbon, MilieuPrestatie Gebouwen, and a circularity-informed indicator (EC+). The EC+ indicator extends conventional EC assessment by incor-porating a limited set of circularity factors: biogenic carbon storage, material replacements, and potential end-of-life benefits.
Unlike conventional tools that rely on the assessment of individual materials, the developed framework oper-ates at the level of elements. An element can be defined as a predefined assembly of one or more building materials arranged in functional layers, corresponding to a specific building part (such as: a floor, a roof or an external or interior wall). In the context of this research, an element was subdivided into three compo-nents, which were termed ’sub-elements’. These sub-elements are categorised as top, structural, or bottom. Sub-elements are manually composed from individual materials to ensure structurally realistic and technically robust assemblies. Complete elements are generated from one top, one structural, and one bottom sub-element in an automated process designed to ensure efficiency and consistency. This process is visualized in figure 1.

Assessing environmental performance at the element level offers significant advantages. It improves impact completeness by including all functional layers, enables consistent integration of circularity parameters such as modularity and connection type, and supports early-stage evaluation even when full material compositions are not yet available. Additionally, it allows physical, structural and circularity-related properties to be assigned to each element. This enables to filter out undesired configurations later in the process, based on project specific requirements.
The tool is furthermore supported by a structured element database, the purpose of which is to facilitate the storage of the aforementioned data. This enhances assessment efficiency and accuracy, and supports early-stage evaluation and cross-project data reuse by preserving validated elements.
This research also developed a methodology to generate synthetic whole building impact data. Elements, sorted by building part, are combined into complete building configurations (see figure 1). All valid combinations tions between elements are made according to the project building part ratio and user requirements, enabling the calculation of environmental impact values for a large number of hypothetical buildings. This synthetic dataset forms a robust reference against which new building designs can be evaluated and contextualised.
The research was conducted using a research-through-design methodology, integrating academic principles with practical industry requirements. The dataflow of the tool consists of three modules: input, process and output (see figure 2). It utilises minimal early design inputs, such as gross floor area and material categories, to estimate whole-building environmental impact values. The process module of the tool was developed in Grasshopper, with supplementary support from Excel and Power BI, enabling real-time calculation, data structuring and saving, visualisation, and live performance feedback.

The validation process confirmed that the tool performs with high accuracy and meets the key requirements defined at the outset of the research. These requirements were initially established and subsequently refined through a thorough review of the relevant literature and current practices in the building sector.
The developed tool offers a reliable and extensible foundation for translating sustainability ambitions and regulatory obligations into practical application by embedding environmental impact feedback into early-stage workflows. This integration supports iterative decision-making and encourages the use of low-carbon and more circular materials before critical design decisions are finalised. The tool’s real-time feedback functionality allows users to explore impact variation under project input uncertainty.
Although the tool was developed with the involvement of different stakeholders, it has not yet been applied in a real-world design process. Consequently, its impact on design outcomes remains to be empirically validated.