Steven Butler
By incorporating sustainability into the design process, project teams can inform better decisions and improve energy efficiency throughout the life of a building.
The Intergovernmental Panel on Climate Change warns that drastic changes are needed to limit the increase in global temperatures to 1.5 degrees Celsius by 2050. Over that same timeframe, the global population is expected to grow to 10 billion people, creating a huge need for new buildings.
Due to this confluence of events, project teams have an enormous opportunity (and, some would say, responsibility) to make buildings more energy-efficient. Increasingly, this is happening early in the design stage, as Building Information Modeling (BIM) and Building Energy Modeling (BEM) tools give teams the ability to quickly test different options to optimize performance.
Already, BIM is revolutionizing the AEC fields, as the move from 2D to 3D workflows is helping teams to improve accuracy and automate routine tasks. Although BIM is already having a positive impact on the energy performance of buildings, there are opportunities to push this impact even further – and better incorporate BEM tools that are specifically focused on energy efficiency.
I recently co-authored a white paper with Bertrand Lack of Schneider Electric titled “Bridging BIM and BEM,” which explores different ways for design teams to limit the carbon footprint of their projects. For anyone serious about optimizing energy performance, I suggest reading full report here.
Here are some highlights from the report:
BIM Is already improving efficiency
BIM is helping to accelerate the adoption of “design for manufacture and assembly,” or DfMA, which can cut down on material waste, cost and project timelines.
Also, the high level of detail inherent to BIM helps designers create more accurate energy models; in an instant, a designer can see the thermal impact of different window placements or building orientations. Recently, these models have begun incorporating performance data from real-world buildings, helping to improve the accuracy of energy models even more. And cloud and IoT integration are set to provide even more and better information in coming years.
Finally, BIM enables generative design, allowing teams to input design goals (such as cost constraints or efficiency benchmarks). Then, the software itself explores different permutations and generates an array of design alternatives for project teams to consider.
The evolution of digital twins
The BIM design process culminates in the creation of a collection of “digital twins” – digital models that represent the physical components of a building. If digital twins were perfectly aligned to their real-world counterparts through links to appropriate technology they could perfectly capture performance, helping to optimize both building design and operations.
In practice, however, digital models are primarily focused on dimensional and geometrical information, rather than information about the performance of electrical, heating, and cooling systems – information that is not readily available from most manufacturers. What’s more, there aren’t currently any universal data format standards for this type of information, making it impossible for teams to import these characteristics consistently across all BIM applications.
Another limiting factor: although changes inevitably occur between the design stage and the end of construction, BIM models aren’t always updated. As a result, building operators are often left with a digital twin that reflects the design team’s original intent, but does not accurately represent the as-built asset.
As data standards – and integration with IoT systems – improve, digital twins will become increasingly valuable.
The Schneider Electric Technopole building was designed using the Revit platform. The building’s digital model is a true mirror of the ‘as built’ construction and will soon be connected to the operating data of the building to be used to support daily operation.
Connecting BIM to BEM
BEM tools can either be integrated within a BIM platform, or used as an external tool. In either case, BEM solutions typically use information from BIM models (including information about building envelope, building structure, equipment, and control scenarios) as the basis of their calculations. Autodesk Insight is integrated with Revit and automatically creates energy models, from early concept to detailed design.
However, work remains to be done to bridge the gap between BIM and BEM solutions. While BIM models have near-comprehensive information about building elements and objects, they do not necessarily have all of the characteristics needed for comprehensive energy analysis. To adequately inform energy modeling, BIM models need to include information about the power consumption of equipment and the heating or cooling capacity of HVAC equipment, at a minimum. And because there’s no established standard for defining energy-related properties, project teams often must rely on country-specific standards.
Data transfer between models can also be challenging. When a BEM tool is integrated with a BIM solution, this process is obviously simplified; however, when teams use separate tools from different vendors, they frequently need to use error-prone data extraction processes.
An example of integrated BEM tools within a BIM platform – Insight and Revit.
In short, project teams have more access to information about buildings than ever before, and this information is critical to helping teams optimize performance, improve efficiency, and ultimately help combat climate change. However, this work will require greater levels of energy-specific information from equipment manufacturers, more integration of real-world performance data, and increased standardization.
To learn more, click here to read the full report.