"Failed to build fen srf" in importIdf


I am doing a simulation to evaluate the impact from EC-windows on UDI and the use of energy for heating and cooling in a building.

When I try to import the idf-file to check my geometry before the EP-simulation I get the message shown in the picture below from the idf-importer.

I have tried to generate the window with the ratio based window creater and tried another climate file. I have also tried the runEPSimulation-component.

Is there anybody who knows what to do?


There is no way to say what’s going on without seeing your model! My best guess is that you have a window that touches the edge of the parent surface.

I’m facing the same problem. The windows are not touching the edges.
Please have a look.

I’m a new user, the system does not let me
to upload files so please use this link.

downgrade the open studio 2,7 to 2,5

Hello all!
Unfortunately I got the same problem.
Instead of downgrade OS from 2.7 to 2.5, is there any other option?
Thanks a lot

@chris should know the answer.

As @chris has kindly answered to the same issue in this post, your windows actually are created and do participate in the calculations, however, they do not appear in the final IDF file.


I just wanted to say that I am very sorry for not seeing this conversation earlier and @Mesrop is correct that the answer is in the thread he linked to. Thank you for posting it @Mesrop !

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