167 visningarFörsöket är skapat 20.09.2018
Building Information Models (BIM) provide an effective way to assess and optimize building sustainability performance. For this to work, the BIM needs to represent the intended building. Modeling issues that would skew the results can be automatically detected. We piloted a Model Checker solution thanks to the support of the KIRA-digi program with 50+ real-life models for purposes of building life-cycle assessment. The pilot proved the concept as workable. https://www.oneclicklca.com/bim-for-sustainable-building-design-with-one-click-lca-model-checker/ https://www.oneclicklca.com/bim-based-life-cycle-assessment-guidelines/ https://www.oneclicklca.com/lca-bim-model-checker/
Numerous studies have shown the opportunity of using BIM for building performance analysis, including energy performance, carbon performance, as well as embodied carbon footprinting and life-cycle assessment (LCA) and life-cycle costing (LCC). BIM models capture information about the building, its shape, space distribution, materials, and systems choices as well as construction information, such as sequencing and construction methods, as well as information about the intended products and/or suppliers for these same products. However, anyone with experience in working with real-life BIM models created for other purposes than performance assessment knows that many of the models lack some performance-relevant information. While a number of commercial solutions for checking BIM quality for various purposes exist, none of them can enable robust building LCA. We wanted to develop new, effective ways to test BIM models quality to integrate BIM and Life Cycle Assessment and make integrated Life Cycle Assessment easier and faster for the construction industry.
The prototype version of the Model Checker was rewritten to a commercial grade solution based on the findings. The checker toolkit in One Click LCA now covers two checkers, one Model Checker (for checking the inputs) and one LCA Checker (for checking the quality of resulting LCA). Both interact but work independently. Typically, Model Checker would be used first to review a model received from an architect. Model Checker results can then be used to request the architect to address the issues confirmed as relevant. Only once the results are complete, and also when elements not found in most architectural models, for example, beams and columns, are added, would user run the LCA Checker. LCA Checker, on the other hand, checks the plausibility of the total LCA, irrespectively if data is coming from a BIM, bill of quantities or is inputted by hand by the end user or is a mix of all three.The commercial Model Checker itself was also expanded with scope to address possible classification issues, new types of geometry problems and warnings related to data processing. The LCA Checker, on the other hand, helps users spot clear technical errors in the overall LCA, for example, not having applied enough reinforcement steel to ready-mix concrete, or inadequate fireproofing. We requested real-life BIM models from various businesses for the test. Our resulting test data set comprised of 61 real-life models from ten different countries. All models were received in IFC2x3 format on “as-is” basis without specific requests being provided other than that models should represent day to day commercial practices and not be of above ordinary quality. When building systems and electrical models were left aside, 41 whole (or substantial part) building models remained for the analysis. Importantly, all models that had been previously analyzed by us were left aside to avoid biasing the sample. This means that the results here should represent what you can expect in a project in your day job. We developed a prototype of Model Checker to test these models and see if errors identified correlated with what our experts could identify in the datasets with desktop analysis. A prototype of the checker was able to report correctly some forms of broken geometry and certain types of problems in multi-layer object definitions. Furthermore, the pre-existing One Click LCA platform itself was able to report unclear labeling issues. The prototype testing is concluded.
The project will be of interest for all designers and architects working with BIM who want to incorporate environmental assessments into their workflow.
The project was completed with the support of the KIRA-digi program.
One Click LCA is the Building Life Cycle Metrics software that allows you to calculate Life Cycle Assessment, Life Cycle Costing, Carbon footprint and other environmental impacts in a matter of minutes thanks to easy to use automation. One Click LCA can be used for Ecodesign, Green Building credits, CSR, and Infrastructure, is the highest rated LCA software for BREEAM, and is compliant with more than 20 other Green Building certification schemes, including LEED, Energie Carbone, DGNB, and HQE.
Yes, it did. There is now a commercial solution available based on the results from the study.
We developed a prototype of Model Checker to test these models and see if errors identified correlated with what our experts could identify in the datasets with desktop analysis. A prototype of the checker was able to report correctly some forms of broken geometry and certain types of problems in multi-layer object definitions. Furthermore, the pre-existing One Click LCA platform itself was able to report unclear labeling issues. The prototype of Model Checker provided a number of relevant errors but turned out to be cumbersome as it triggered also a number of false positives or uncertainties in a way requiring many manual checks. All the prototype checks were run against the entire set of data in the IFC model, irrespective of its materiality for purposes of LCA. This means that the scope of potential errors is far higher than in a case where the model is filtered for the scope that’s actually of interest for LCA purposes. Note that the definition here is a report, as some of the reports can be legitimate and represent the building even if some of the data is defined in a way to trigger a report. Reports in these classes resulted on the average therefore to below 10 % of number model objects (where a single external wall face is defined as one object). While no comparison with, for example, LEED v4 scope was done, based on a smaller sample of tests we can expect an approximately fivefold reduction in these classes of issues once the scope of analysis is limited to structure and enclosure. Considering that some reports are not requiring action, the number of reports requiring investigation would be a handful per project. Example of a warning could be that a layer of material is defined with an implausible thickness for the material type in question.
We have already scaled up. We are looking forward to more businesses adopting this solution to increase the number and quality of LCAs they perform for their buildings and, as a consequence, build more sustainably.