BIM Software

The BIM Collaboration Format, or BCF, is one of the most simple and useful standards in the buildingSMART toolkit. BCF exists to track issues as they are identified, reported on and resolved in the course of the BIM process. We spoke in a previous video about the two realms of BIM. On the one side there is a native modelling environment and on the other there is the collaborative environment. Most major issues are identified in BIM coordination meetings, that is in collaborative environment. However, as we are working with IFC model copies, we can’t make any changes here. In the past we would just take screenshoots of the clash or model issue and create a PDF report to send to everyone. This was not a very intelligent way of working. It was also a massive, often uncoordinated, task to track all the issues and check that everyone had delivered on their tasks. Enter BCF. BCF is like the WhatsApp of BIM. It allows you to send model mark-ups, clash reports, and general comments between all project members. Each BCF issue is registered with a unique ID, making it easier to track how many issues are open, who is responsible for what issues, and to see when the issues are resolved. You can also get analytics on how many issues are generated each week and how long they are taking to be resolved. What is particularly cool about BCF is the communication between IFC tools and native modeling software. The BCF will identify exactly which objects are involved in an issue and will even record the screen view. So, when someone opens up a BCF issue in their modelling software they are directed to the exact same view in their model. No need to navigate around the model looking for that one missing electrical socket. When the issue is solved in the modelling software, the BCF is update and this is communicated back to the project manager. So easy. Why didn’t we think of it sooner! Further Resources: www.buildingsmart.org/bim-collaboration-format-explained www.buildingsmart-tech.org/specifications/bcf-releases

IFC, or industry Foundation Classes, is a standard, some would say the primary standard, for openBIM data exchange. IFC is commonly referred to as an exchange format. This is not entirely correct. Firstly, IFC is a schema, not a format. But that is probably a discussion for another time. Let’s focus on the exchange part. The current IFC workflow doesn’t support data exchange to the extent that I can start modelling in one software, make an IFC export to another application and continue modelling uninterrupted. It’s more accurate to think of IFC as a means of referencing or archiving model content. In the previous video of this series we presented IFC as the PDF of BIM. Like PDF, an IFC file is a frozen copy of the original content. It can be viewed, measured, used for clash detection, cost estimation, simulation and innumerable other uses, but should not be edited. An typical IFC workflow could be the following: An architect creates their design model and exports an IFC version to share with the HVAC engineer. The HVAC engineer can reference this file into their own software and use this for coordination. More than that, the engineer can also use the IFC model as a basis for energy analysis. Which is pretty impressive. The IFC transports enough information for the simulation software to read and analyse the IFC spaces in the referenced model. What the engineer can’t do, however, is make a change to the referenced model. For example, if they want to move a wall, or create an opening in the wall for an air duct to pass through, they must request that change from the architect. The architect, back in their own modeling software, then cuts the opening in their model and issues a new IFC file. It must be said, that it is technically possible to edit an FC model, but that is not the intended workflow. Almost all software that import IFC treat the IFC model as referenced copy of the original design. Some tools allow you to make minor edits to an IFC model. For example splitting a concrete slab element for construction phasing, but this is an isolated activity and has no effect on the original design model. The point is that in an IFC-based workflow each discipline remains author and owner of their model content.   Further Resources: www.buildingsmart-tech.org/specifications/ifc-overview