Identifying and Leveraging Potentials for Emission Reduction through Life Cycle Assessment

Articles

Life cycle assessment (LCA) is increasingly gaining importance as a tool for accountability in structural engineering. The SOFiSTiK Life Cycle Assessment Task enables structural engineers to directly determine the Global Warming Potential (GWP) from the calculation model and to systematically compare variants with respect to their climate impact.

Life Cycle Assessment – A Necessary Planning Instrument for Future-Oriented Structural Design

Responsibility for sustainable construction does not lie solely with architects or energy planners. Since the load-bearing structure accounts for around 54% of a building’s embodied emissions, structural engineers should leverage life-cycle assessment to identify the key CO₂ drivers of a design and actively reduce GWP.

Structural Design as a Lever for Reducing Embodied Emissions

Many planning decisions, whether made directly by structural engineers or influenced by them, affect a building’s ecological quality. For example, increasing the concrete strength class raises GWP by approximately 10%, whereas for reinforcing steel, the GWP is independent of strength. In buildings of massive construction, around 18% of CO₂ emissions are attributable to reinforcement. Despite its relatively small volume, it has a significant influence on the structure’s GWP.

Well-founded structural analyses enable a realistic representation of the load-bearing system, providing a basis for identifying and evaluating optimisation potentials at an early stage – such as more efficient material use, appropriate load assumptions, and well-conceived structural solutions.

From Ambition to Practice: The SOFiSTiK Life Cycle Assessment Task

As a provider of innovative software for structural engineering, SOFiSTiK offers the Life Cycle Assessment Task (available since version 2025), an integrated tool that allows direct determination of GWP from the calculation model, including design results such as reinforcement quantities. Based on the materials and quantities used, global warming potentials are calculated for the life-cycle phases A1–A3 (production), C3 (waste processing), and, optionally, D (recycling potential).

Through direct integration with the ÖKOBAUDAT database, material definitions can be automatically linked with appropriate Environmental Product Declarations (EPDs) or

manually adjusted. The result is a detailed report evaluating emissions by material and, using SOFiSTiK groups, also by levels, component types, or cost groups.

Variant Comparison as the Key to More Sustainable Decisions

The assessment from the Life Cycle Assessment Task refers exclusively to the load-bearing structure and does not include finishing works or building services. This allows planners to compare different structural variants with respect to their ecological impact in isolation and independently of other disciplines.

With the integrated Excel export function, GWP results of different model variants can be saved and visually compared. This creates a transparent basis for variant comparison and for assessing structural solutions from a sustainability perspective with minimal additional effort.

Early Evaluation of Structural Variants Using Intelligent Interfaces

SOFiSTiK offers a wide range of modelling and planning platforms. Fully BIM-integrated structural planning is possible with Autodesk Revit, enabling life-cycle assessment parameters and results from SOFiSTiK to be linked to model data. This significantly facilitates regular exchange on ecological quality with other planning stakeholders.

In early planning phases, parametric variant studies are often used. For this purpose, SOFiSTiK provides interfaces to the 3D modelling software Rhinoceros and the associated visual programming tool Grasshopper, enabling continuous, integrated process chains.

GWP-Vergleich eines Gebäudeentwurfs mit drei verschiedenen Stützenrastern mittels des SOFiSTiK-Ökobilanz-Tasks

A webinar (German) available on the SOFiSTiK website demonstrates how variant parameters defined in an Excel spreadsheet can control parametric modelling in Grasshopper.

Following structural design and subsequent life-cycle assessment in SOFiSTiK, the variants are evaluated in Excel, enabling direct comparison of GWP values and early identification of optimisation potential. SOFiSTiK thus provides integrated tools that enable structures to be designed not only efficiently but also sustainably, making structural design an active lever for future-oriented, resource-efficient construction.

Sources:

[1] Arup; WBCSD (eds.), Net-zero buildings – Where do we stand?
[2] Attitude Building Collective e.V. (2024), Design Panels – Life Cycle Assessment in Structural Engineering
[3] Weidner, S., Mrzigod, A., Bechmann, R., Sobek, W. (2021), Embodied emissions in the construction industry – inventory and optimisation strategies. Beton- und Stahlbetonbau, 116: 969–977.