LBNL Window to BSDF for Daylight simulations

Hello everyone,
I wanted to test LBNL Window software for generating BSDF to test in Daylight simulations with Ladybug Tools. However it does not run since there are some DLLs missing. Reinstalling did not solve the problem. Has anyone experience the same issue?

Sorry if this is not relevant for the Radiance forum.


Hi @arlind.dervishaj,

I’m guessing you need to install the Intel Fortran redistributable package. When you download LBNL WINDOW from their website, you will see an option to download the redistributable libraries.

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Thank you @Nathaniel_Jones ! It works

Hi all,

I’m trying to generate a BSDF file for an external, operable, horizontal shading device (venetian blind in English?), something like this:

I would use the BSDF file as a custom blind in Climate Studio for Daylight analysis.

I think I managed to follow the installation procedure, but when I press Calc (F9) Window just crashes.
I might be doing something wrong – I’m not sure, never did this before. For this reason, it is not clear to me if I should build the glazing assembly and add the external shading, or just add the shade layer to the glazing system?

In this case, the generated BSDF will account for the whole assembly, or should I somehow be able to generate the shading layer alone?

I was trying to follow this document, but no success so far:

This is a really common setup in my country, and Climate Studio is the easiest way to show the students the effects of different glazing setups + dynamic shading, but its default library doesn’t have any of this kind of shading, and I’m awfully a beginner in Radiance.

Any help would be appreciated!

Hi furtonb,

I’m not too clear about if Window gives you a combined or separate BSDF. Nor will I be very helpful in troubleshooting Window (you may want to post in the Window forum).

I can clarify one thing though: for modelling in ClimateStudio, you need to make sure you have a BSDF of the blind only, because CS combines the glazing material and the shading device into a single BSDF at runtime.

IEA SHC Task 61 Subtask C did extensively measure and compute BSDFs for a HELLA ARB 80 exterior blind. Those measures don’t seem to be public, but perhaps you could ask after them.


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Thanks, @J_Alstan_Jakubiec !
Do you have a documentation how the blinds in the CS database were generated?
I’m definitely doing something wrong, as the “shading only” glazing system calculation is crashing - if I add a blind with the same settings to a glazing assembly containing glazing layers and e.g. an air gap, I can calculate it.

@Greg_Ward I saw your name among the authors in the PDF that Alstan linked, do you think it would be possible to get access to the BSDF file for that Hella shading device?

Many thanks, I appreciate the answers!

I wasn’t working directly with the BSDF data for this paper – maybe ask @David_Geisler-Morod1 if he has access to it (and permission to share)?


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Hi furtonb!

Within the IEA Task 61 several institutes generated data for a venetian blind system and we compared the results and found good agreement (see the documentation @J_Alstan_Jakubiec referred to).
I uploaded the BSDF file for the blinds (without glazing) that we generated here at Bartenbach for you here: IEA_T61_Blind_BB.xml. You should be able to use that in CS I guess.

Best regards,


Those come from the Complex Glazing Database.


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