Integrating Revit-API and GBS-API to Optimize Building Energy Performance

Who is this for: Architects, engineers, software vendors, developers, and research institutions involved with BIM and building energy analysis and interested in workflows for design optimization.

Takeaway: This post introduces an application that is created by integrating the Revit-API and GBS-API to automate the process of optimizing building energy performance. Simulating and analyzing the energy performance of a building in the real world is a time and labor consuming process. The application created enables users to automate this process and significantly reduce the time and effort required to achieve an optimized design. 

Author: Mohammad Rahmani Asl and Wei Yan, BIM-SIM LAB, Texas A&M University

In order to automate the building energy performance optimization process, an application has been developed using the Revit-API and the newly released GBS-API to enable the interaction between Revit and GBS. 

This application provides a user interface inside Revit to generate new design options based on user defined parameter changes in a Building Information Model. Then it creates gbXML files for each design option and exports them to GBS to perform energy simulation. The application retrieves the energy simulation results automatically from the GBS website and finds the optimal solution for the project based on energy cost. Finally, it updates the BIM model to the selected solution and provides the simulation results to the user. 

The following case shows how the tool enables design professionals to optimize the building performance. 

In this case, a sample model of Autodesk Revit is used. The goal for this optimization problem is to minimize the building energy use and get the LEED daylighting credit with changing the windows size parametrically.

As the first step of model preparation, a parametric window family is created with “Width” and “Height” instance parameters. By changing these two parameters of the windows, a few design options have been created for this case. In the next step, in order to have an accurate simulation the building is divided into a few thermal zones based on rooms. The following figures show zones and analytical surfaces created for this step. 

In the next step the application creates a gbXML file for each design alternative and uploads it to a GBS project that is created automatically using the Revit project information on the GBS server. When the simulation is done in GBS, the application retrieves the result of building energy analysis from the GBS website. Using the whole building energy use and LEED daylight results the optimal size of the windows is calculated which is shown in the following graph. In this graph the horizontal axis is window size. The black and red lines show whole building energy cost and LEED credit respectively. The optimum result is highlighted in this graph as the desired solution.

The following video demonstrates the whole process. In this video a simpler building has been chosen for better demonstration.

 

Tell us what you think: We would really like to hear your thoughts about this application and the benefit of automating building energy performance optimization. Do you find it interesting and would you use it?

 

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Comments

[Andre]

Where is the download link? This would be an amazing tool to have and I would be using it today on several projects.

What restrictions are there? for example, file size, building complexity, etc?

Can this be tied to other parameters? for example, sun shade width and depth?

Thank you

[Mohammad Rahmani Asl]

Hi Andre,

Thanks for the comment. I am glad to see that you are interested in our work. This application does not have any specific restrictions regarding project size and complexity. It means you can implement it on any project that can be handled by Revit and Green Building Studio. It can be tied up with many parameters too.
This is a research project at Texas A&M University which is supported by Autodesk Building Performance Analysis team and right now it is under development. We have created a prototype for internal testing but haven't completed a product for end users. We are working to create a Revit/GBS API plug-in with a user interface where the users can interact with the application efficiently.

I hope that we can release the plug-in in the near future. In the meantime, we will appreciate it if you could provide some thoughts on the needs for the application based on your projects.

Mohammad Rahmani