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Adding Non-Rectangular Windows to an OpenStudio Model

asked 2015-07-24 08:46:22 -0600

dpud12 gravatar image

Is there any way to have non-rectangular windows in an OpenStudio model? Currently, whenever I have a non-rectangular window an error is thrown by EnergyPlus when I run the simulation. I can see that if it is a restriction of E+ that it would be harder to get around, but maybe in the future a good auto feature of OpenStudio would be to convert non-rectangular windows to a series of smaller rectangular ones.

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An auto-window correction has come up but not on our radar for now. There are two approaches for this. One is to have a method that triangulates the window, possibly adding in a small base surface space between windows (just to aid modeling tools, I don't think E+ requires that gap). A second approach would be to create a single window with the same position and area. In a case where the base surface is also non-orthogonal, like a circle the method could use e sub-surface multiplier to get to the correct area. If you plan to run Radiance you would add this method downstream of that.

David Goldwasser gravatar image David Goldwasser  ( 2015-07-24 09:50:16 -0600 )edit

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answered 2015-07-24 08:57:30 -0600

As far as I am aware, you can only have rectangular or triangular windows and so if you have an unusual shaped window you need to break it down into those two shapes for E+ to be happy. So in your case if you break your non rectangular into multiple triangular you should be fine.

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Thanks @Annie Marston good to know that triangular is also an option.

dpud12 gravatar image dpud12  ( 2015-07-24 09:20:31 -0600 )edit

answered 2015-10-31 19:37:59 -0600

Krishnan gravatar image

This should be a high priority item for E+ team - I am seeing this a major issue for BIM tools to use E+ without creating multiple pieces of window glass of several quadrilateral and/or triangular pieces

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@Krishnan, you should add this request to the UserVoice site (

__AmirRoth__ gravatar image __AmirRoth__  ( 2015-11-01 08:23:10 -0600 )edit

Thanks Amir, added this to user voice - hoping it will be heard...

Krishnan gravatar image Krishnan  ( 2015-11-01 10:08:47 -0600 )edit

@Krishnan, the uservoice site is the place to discuss, refine, and prioritize features. If enough people think this is important and we can get a good understanding of what is needed, we will do it.

__AmirRoth__ gravatar image __AmirRoth__  ( 2015-11-01 16:28:56 -0600 )edit

For any users stumbling onto this. Around the same time this Q/A was posted, EnergyPlus seems to have the added functionality to process irregular 4-sided subsurfaces (I'm assuming convex). There remains at least 2x open, new feature requests for EnergyPlus (here & here) to allow processing of (irregular) subsurfaces with more than 4 vertices.

Denis Bourgeois gravatar image Denis Bourgeois  ( 2021-06-16 06:26:15 -0600 )edit

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Asked: 2015-07-24 08:46:22 -0600

Seen: 365 times

Last updated: Jul 24 '15