Scaling up Building Sustainability Assessments with BIM Model Checker Tools
Sustainability of buildings is an essential topic – buildings and construction consume almost half of raw materials and one third of energy in Europe. Therefore, scaling up the building sustainability assessments and making them faster and more reliable is a key challenge.
Building sustainability is evaluated with a Life Cycle Assessment (LCA). An LCA is a quantitative method of assessing a building’s environmental impact throughout its life cycle, i.e., procurement, construction, operation, and decommissioning. The assessment allows owners to optimize the entire building process from a life cycle cost perspective instead of resorting to short-term sub-optimization.
Building information models (BIMs) can provide a lot of useful information for a life cycle assessment. However, the models have to meet certain criteria to be usable. Bionova created a prototype to test how well a model checker could automatically verify the quality of a BIM.
BIM Allows LCA Automation
At its core, the LCA process involves multiplying quantities of building materials with their respective environmental impact profiles. Architects and engineers typically provide an LCA for a client during the design phase. Creating an LCA is not a small task, which is why designers often hire specialists to do it. However, if the design firm has a virtual model of the design, they can perform the assessment with the appropriate software.
“Our One Click LCA makes special knowledge redundant and gives the designers the power to do the LCA by themselves,” promises Panu Pasanen, CEO of Bionova. “With our automated solution, you can do the assessment in hours instead of days or weeks.”
Bionova’s tool integrates with commonly used design software, including Autodesk Revit, IES-VE, and DesignBuilder. It can read data from application-neutral IFC models, spreadsheets, and so on. Manual data input is also possible using the web interface. The software complies with international standards and several certifications.
A Model Checker Prototype
The trustworthiness of an automated LCA depends on the quality of the data available. There are two issues regarding data quality: technical correctness and overall data completeness. Until now, problems with the models have become visible only after the designer has completed the assessment.
“If you want to use BIMs for any type of automation, the models have to meet certain quality criteria. You need a model checker to verify the quality and suitability,” Pasanen explains
There were no checkers for LCA purposes, but Bionova developers had an idea for how to build one. They decided to build a prototype to test the concept with real-life data. In the fall of 2017, they received funding from KIRA-digi, a Finnish government-supported digitalization program, to experiment with a model checker. The experiment concluded in May 2018.
The experiment included three main parts. Bionova first defined the method for verifying the concept. Second, they collected 61 BIMs in the IFC format from 10 countries. Of the original models, 41 were deemed useful for the experiment. Finally, Bionova created the prototype software, ran it against the models, and analyzed the outcome.
The Experiment Led to Commercial Development in One Click LCA
Bionova’s experimentation proved that their original concept was viable. It showed that the automated check could identify errors in the models in much the same way as a team of experts did in a desktop analysis. For example, some of the errors were related to broken geometry and multi-layer objects. The initial prototype triggered false alerts too, but the developers could sort that problem out later.
“Currently, we can use architectural and structural models or a hybrid thereof. HVAC design models unfortunately do not present objects in a format that would allow LCA automation today,” says Pasanen. “Furthermore, the design phase and the level of detail limit what can be obtained out of the models. A wall in an early-stage model is a solid block, whereas in the later stages, it consists of several layers with material attributes. Early stage models can be used, but for those we have a different solution.”
After the successful experiment, Bionova rewrote the prototype software as part of One Click LCA. It became Model Checker, which is now available for commercial use for their One Click LCA users. They also created LCA Checker, a product for probing the quality of the resulting LCA.
Bionova serves a global customer base of forward-looking architectural and engineering firms. In December 2018, the company conducted a survey of Model Checker users. Over 90% of the respondents found it useful.
Model Checker creates a list of issues the designer should fix in the model. That functionality serves both designers and clients. Pasanen thinks checkers will also be of value to building authorities.
“I believe BIM model checkers will be very useful in building permit processes. They allow automated inspection of compliancy with regulations and LCA requirements while making sure the quality of the model is adequate,” Pasanen predicts.
To learn more about the experiment, visit the project page at kiradigi.fi.
To learn more about One Click LCA, visit the website www.oneclicklca.com.