When it comes to calculating, considering and reporting on embodied carbon, many within the construction and engineering industries are perhaps still finding their feet. Indeed, it can be an initially overwhelming process, requiring an understanding of what tool to use, why and when. Read on, as we try to take away some of this confusion…
Within the built environment, around 50% of a building’s total embodied carbon is specified during Stage Two of the RIBA Plan of Works (PoW): Concept Design. As such, this is clearly a priority phase of the wider construction sequence where attention needs to be paid to reducing these carbon emissions and designing greener.
During the Concept Design phase, engineers will utilise structural design and analysis tools, such as Tekla Structural Designer, to plan out the building or structure. By making decisions regarding the grid type, column layout, load transfers and substructure (for example), engineers will determine the most efficient, sustainable and cost-effective structural design.
Easily view the lowest utilisations alongside the highest carbon members in Tekla Structural Designer.
Generally speaking, Stage Two of the RIBA PoW equates to Stages A1-A3 of the Carbon Lifecycle sequence, which is when the Carbon Calculator tool in Tekla Structural Designer comes into play. This tool enables engineers to bring carbon into the design and decision-making process, in as much the same way as cost, time and quality drivers already are. With the live carbon calculations and the added insight offered into the performance of the building, it can inform better and greener decisions.
After the structure of the building has been decided, the project will then move into the subsequent RIBA PoW stages: Spatial Coordination (3) and Technical design (4). It is here that the 3D model becomes far more detailed and specific. Structural modelling software, such as Tekla Structures, enables detailers to “spec up” the building, detailing all of the individual connections, welds, plates and bolts – in the case of a steel framed building. While they may be small components, there can be thousands and thousands of them within a single model. It’s also at these stages that other contractors and disciplines will add their information and data into the 3D model, such as MEP services, cladding, fire protection and utilities, to name a few.
MEP services brought into Tekla Structures software.
It’s understandable, therefore, that bringing this level of additional detail into the model will also bring with it additional carbon, which is why continuing to report on carbon as the project progresses is so important. While Tekla Structural Designer can offer educated assumptions on carbon, it is Tekla Structures that brings the detail, with the final result being a constructible, as-built model.
This is why it’s important to have a modelling software with a high Level of Detail (LOD), satisfying the Level of Information Need. Put simply, the more accurate the model, the more accurate your carbon report will be. This also means that the embodied carbon figures can differ, depending on what modelling software is used on a project.
As a result of Trimble’s collaboration with OneClick, customers can benefit from the live link between One Click and Tekla Structures, enabling users to view and generate carbon reports based on the detailed, constructible model.
Taking a step further and moving out of the construction phase, into stages B1 – C4 of the Carbon Lifecycle sequence, there are more industry tools available for contractors to use. For example, as the name suggests, One Click LCA software covers the full lifecycle of a building, from cradle to grave, taking into account factors such as: the thermal efficiency of a building, its usage, operational carbon, maintenance, potential refurbishments and its end-of-life.
The IStructE also offer similar resources and spreadsheets, including useful guides on how to calculate embodied carbon.
While embodied carbon may still be relatively new to the industry and many are still getting accustomed to this different way of working, there are a variety of tools available to help engineers, contractors, detailers and fabricators deliver this vision of a greener future.