AECOsim Building Designer CONNECT Edition AECbytes Review (October 5, 2017)

I last reviewed Bentley’s multi-disciplinary BIM application, AECOsim Building Designer, in 2012 when it was in the V8i generation. A lot has changed since then with regard to Bentley’s technology. It has a brand-new CONNECT generation, which features dramatic improvements over the earlier V8i generation including speed, connectivity, mobile support, cloud capability, and interoperability with other applications. Bentley first introduced the CONNECT edition at its 2014 YII (Year in Infrastructure) conference and has been gradually releasing the CONNECT editions of all its applications, starting with ProjectWise, MicroStation, and Navigator at YII 2015 and many more of its design, analytical, construction, and reality modeling applications at last year’s YII conference. The CONNECT edition of AECOsim Building Designer has just been released and this review takes an indepth look at it to explore the new features and enhancements in this major generational update of the application.


The most visible change in the new edition of AECOsim Building Designer is its interface. The starting experience has been completely retooled, so that when you now launch the application, you are greeted with a Welcome page before moving on to the working session. As shown in Figure 1, the Welcome page provides links to examples, how-to videos, learning events, additional training, news, and social media. The idea is to provide easier and more immediate access to the latest learning content before moving on to work with the application. 

Figure 1. The Welcome page that opens up when AECOsim Building Designer is launched.

Once you move on to start a work session, you can choose to create a new project or work on an existing project. Creating a new project is done by choosing an appropriate “workset” for the project type—essentially like a template with settings customized for different building types, locations, company standards, etc.—from a broader category known as a “workspace.” Once the selection is made, the project is opened in the brand new ribbon interface shown in Figure 2.

Figure 2. The new ribbon interface of AECOsim Building Designer.

In addition to providing the interface with a clean and modern look, the ribbon interface also better organizes the large number of tools in AECOsim Building Designer in distinct categories that are easier to find. Thus, there are the four main tabs for each of the building disciplines that will be using the application to create their disciplinary models—architecture, structure, mechanical, and electrical. Additional tabs such as Data/Reporting, Analysis, Drawing Production, and so on contain tools that would be used by all disciplines. A Properties panel on the right shows detailed information about a selected element. As in most applications with a ribbon interface, a Quick Access toolbar at the top provides access to the most frequently used commands such as Undo, Redo, Print, Save, etc. For this application, it also provides the ability to choose from different workflow types such as AECOsim (BIM tools), reality modeling (point clouds), drawing, modeling, and visualization. The ribbon tools change based on the workflow type that is selected, as shown in Figure 3.   

Figure 3. Selecting the Drawing workflow from the Quick Access Toolbar changes the ribbon tools to those related to drawing production.

Other notable interface enhancements include the ability to open up a suite of navigation tools at any spot by using Ctrl+Shift+right click (Figure 4) and a Search box to quickly open up any required tool without having to look for it in the ribbon. If you are logged into Bentley Connect (every user needs to have a Bentley account), you can access Bentley Connect Advisor, an in-product tool to access context relevant learning material. Also, the overall speed and responsiveness of AECOsim Building Designer have significantly improved, now that it is a 64-bit application—editing is easier and views are refreshed much more quickly, even for large and complex models.  I was pleasantly surprised by how fast it was, compared to similar applications, on my computer, which has decent specification but is not a high-end graphics workstation.

Figure 4. The set of navigation tools that can be opened at any point of the screen for quick access.

Range of Capabilities

AECOsim Building Designer has been a multi-disciplinary BIM application since the V8i edition, and it has the full gamut of tools for creating architectural, structural, and MEP models, with dedicated ribbon tabs for each disciplinary toolset. Thus for architecture, there are the tools for modeling walls, doors, windows, floors, roofs, etc., that you would find in any architectural BIM application (Figure 5); the ability to create parametric BIM content; push/pull solid, surface, and mesh modeling that can be used to create any form at the conceptual design stage; and the ability to import a space program from an Excel spreadsheet and track those spaces throughout the life of the project. Similarly, you can create comprehensive structural, mechanical, and electrical models using the tools in their respective tabs (Figures 6 and 7).

Figure 5. Using the Door tool from the Architectural tab to place a door in the model.

Figure 6. Creating a structural model for the project using the tools in the Structural tab.

Figure 7. An HVAC model of one of the spaces in the design created using the tools in the Mechanical tab.

As is evident from the above images, the fundamental approach of Bentley to BIM hasn’t changed—using a federated rather than a centralized building model.  This involves creating several working models that are referenced together to create a disciplinary model, which in turn is referenced with other disciplinary models to create the final or “master” building model (Figures 8 and 9). While the exact project organization can vary, it is most typical to break down models first by discipline, then by floor or space, and so on. Multiple levels of hierarchy are supported, so for example, for a larger project with multiple buildings, the first level could be a building rather than a discipline. While this federated approach can be somewhat involved and requires advance planning to set up a project, it allows the work to be distributed easily across project teams and keeps the individual project files small and manageable.   

Figure 8. A simple example of how a federated project would be structured in AECOsim.

Figure 9. A higher level model of the project shown in Figure 2 to 7. The Reference hierarchy shows all the individual models that it is composed of.

While the federated approach and the extensive disciplinary BIM modeling capabilities are not new to the CONNECT edition and have been the hallmark of Bentley solutions for many years, what is new to the CONNECT edition is a powerful and versatile visualization tool called Display Rules, which can be used to customize the display of building elements in a model or drawing based on their properties. This provides enormous flexibility in color-coding models or drawings based on desired criteria. An example is shown in Figure 10, where a Display Style with a Display Rule to color code walls based on their fire rating has been created and applied to all the active views. This Display Rule also displays all the other elements in the view as light grey and semi-transparent. The exact specifics of this rule are defined in the Display Rules dialog, as shown.

Figure 10. Applying a Display Style with a Display Rule that can be customized as required.

Additional capabilities in AECOsim Building Designer include algorithmic modeling using GenerativeComponents (Figure 11), which is included with the application (but needs to be selected during installation); reality modeling in real time with the point cloud data from laser scans using  Descartes (which again is included with the application but needs to be selected during installation); highly photorealistic visualization using the built-in Luxology rendering engine that even allows quality draft renderings to be created very quickly (Figure 12); the option to connect further to LumenRT, the real-time animation and visualization application that Bentley acquired a couple of years ago and which wowed everyone at the YII 2015 conference:  the ability to create drawings from models that can be dynamically updated as the design progresses or “frozen” at a specific stage; full-fledged documentation capabilities; and improved support for operations and facilities management with the ability to add BIM data to CAD legacy graphics, use display rules to highlight different FM-related aspects of the design (Figure 13), attach product data in the form of PDFs or images to building objects, and a COBie DataSet Extension that enables easier export of the model to COBie spreadsheets.  

Figure 11. Using GenerativeComponents within AECOsim Building Designer for roof design.

Figure 12. Drafting renderings created quickly using the built-in Luxology engine.

Figure 13. Applying a Display Style with a Display Rule to highlight the planned floor cleaning schedule of one of the spaces in the building.

Intra-operability and Interoperability

As part of the CONNECT edition, AECOsim Building Designer has seamless, translation-free, “intra-operability” with Bentley’s full portfolio of design, analytical, and construction modeling applications across all of the many industries it serves  (Figure 14). All the CONNECT applications not only shared a common platform and data format—the DGN file format—but are also connected to each other to the point where you can just open a model created in any Bentley application in any other Bentley application, making it much easier for a Bentley user to work in a multi-disciplinary environment. So, for example, for a Rail project, the track design could be done using Bentley Rail Track and the station design using AECOsim Building Designer, and both model types could be seamlessly brought into either application.  The data connectivity for the CONNECT solutions happens through the “cloud,” and more specifically through Microsoft’s Azure cloud services.

Figure 14. The large number of Bentley solutions in the different industries it serves.

For working with non-Bentley applications, AECOsim Building Designer can directly open files in a large number of file formats such as DWG, DXF, 3DS, SKP (SketchUp), 3DM (Rhino), RFA (Revit Family File), and several more, as shown in Figure 14. And of course, it can also import files in the OpenBIM IFC file format to work with applications such as ArchiCAD, Allplan, Tekla Structures, and so on.

Figure 15. The large number of file formats that can be directly opened in AECOsim Building Designer.

In addition to supporting the IFC format for interoperability, Bentley has also developed its own open format called the i-model to facilitate easy, secure, and data-rich exchange of building models between applications. The i-model is best defined as a “container for AECO information” and Bentley provides the option to publish an i-model not only from all of its own applications but also free plug-ins for some popular third-party applications such as SketchUp and Revit to create i-models from them. Not only is an i-model information-rich and can be used to share data with other applications more accurately, it also has significant compression capability without any loss of fidelity. This is illustrated in Figure 16, where a 13 MG Revit model is only a little over 2 MB when converted to an i-model.

Figure 16. A 13 MB Revit model (top image) is only 2.3 MB when published to an i-model that is subsequently opened in AECOsim Building Designer (lower image).

Analysis and Conclusions

AECOsim Building Designer continues to be one of the most comprehensive multi-disciplinary BIM applications available for the AEC industry, and the fact that it was one of the last of Bentley’s applications to be updated to the CONNECT edition reveals its complexity. There are so many aspects to it, so many capabilities, and so many ways in which it can be used that it would be extremely difficult for a single person to master all of it. This also happens to be the case for AEC projects that typically rely extensively on multiple specialists, so in that respect, AECOsim Building Designer works perfectly, providing the necessary tools to each one of them to be able to do their tasks effectively. Bentley’s federated approach to BIM makes it a lot easier for each of them to work on their own parts of the project and then stitch it together into a combined whole. As long as there are large and complex AEC projects that require multiple disciplines and specialists, there would always be a need for an application like AECOsim Building Designer.

The CONNECT edition of the application significantly overhauls the user interface, making it more modern and up to date with the times. And given that the application involves a significant learning curve, the emphasis on putting the learning content upfront and easily accessible throughout the application will serve existing and new users very well. The new display rules visualization capability is extremely powerful and versatile, allowing any kind of viewing customization to be applied to any building element based on any of its properties. The option to have add-ons for computational modeling (with GenerativeComponents), reality modeling (with Descartes), and real-time visualization (with LumenRT) adds even more power to AECOsim Building Designer, and the intra-operability with Bentley’s extensive portfolio of other applications enabled by the CONNECT edition allows it to be used across multiple industries. There is also the i-model and native support for a wide variety of other formats that allow it to not just to inter-operate with non-Bentley applications, but to become the hub for bringing all these different models together into a consolidated whole.

The only downside to the federated approach is the difficulty in setting up the project—for which there is no intuitive interface—and the lack of associativity between the building elements located in multiple files. So, for instance, changing the height of a wall in one file will not impact any elements in another file, even if they were from the level above—they would need to be manually updated. But this has always been the main weakness of the federated approach, as pointed out in the extensive “federated versus centralized” debates we had in the early days of BIM. It seems as though the matter has been laid to rest, with the recognition that for a large and complex project, it is inevitable that the model will be broken up so different team members can work on different parts of it simultaneously.

That said, I wish that even within its federated approach, AECOsim Building Designer would have some “smarts” similar to the new rule-based Stair and Railing tools in the recently released ARCHICAD 21. Overall, BIM applications need to ramp up their intelligence quotient so that they are not as labor-intensive to use. While the labor involved in AECOsim’s federated setup seems unavoidable, there can at least be individual disciplinary smarts in the application that would automate repetitive tasks for architects and engineers. Now that Bentley has overhauled the user interface of AECOsim Building Designer, it will hopefully focus its efforts on developing these smarts. In particular, this would be crucial to attracting younger generations to its tools. I find it difficult to see today’s kids spending the time required to master a complex application like AECOsim Building Designer in its current form, given that the other technologies they consume are constantly getting quicker and easier to use.

About the Author

Lachmi Khemlani is founder and editor of AECbytes. She has a Ph.D. in Architecture from UC Berkeley, specializing in intelligent building modeling, and consults and writes on AEC technology. She can be reached at

AECbytes content should not be reproduced on any other website, blog, print publication, or newsletter without permission.

Related Archive Articles

  • Bentley's Year in Infrastructure 2014 Conference
  • Details on Bentley's CONNECT generation of software and a guest keynote on the new High Speed Rail project proposed for London on which the use of BIM is being seen as the "lifeblood" of the project.
  • Extending BIM to Infrastructure
  • Now that BIM has conquered the building industry and is here to stay, this article explores the application of the same "information modeling" concept to infrastructure.
  • Bentley's Year in Infrastructure 2013 Conference
  • The main updates from Bentley at its Year in Infrastructure 2013 Conference, including the official launch of its cloud software service called Bentley CONNECT, updates to its suite of mobile solutions, and new and upcoming features in MicroStation, ProjectWise, and AECOsim Building Designer.
  • Bentley AECOsim Building Designer V8i
  • This review explores the capabilities of Bentley's new integrated multi-disciplinary BIM application, AECOsim Building Designer, which combines all of Bentley's diverse BIM applications for different disciplines in one single product.