sDA calculation


I think that there could be an error in the ouput from the sDA component.
The sDA calculated from the DA results gives me a different result than the one from the sDA component.

Am I doing the right calculations?

Best regards,


Hi, I am having the same issue. It seems sDA is too low (almost 2 or 3%) for north oriented windows with descent sizes. One thing I notice is that DA is insensitive toward occupancy schedule.

I used the same approach as you illustrated in the image to calculate sDA but when I disconnect the schedule, the calculated sDA did not change! So my interpretation was that probably DA is insensitive toward the schedule. But UDI got updated.

Hi @saram,

Sometime you need to disable and enable again the component, but I do not think that this is the case.
I checked the DA and sDA output for the same simulation but with different schedules, and I can see the changes.
Maybe the problem is with the schedule component. Check the values with ladybug 3D chart component.


Thank you for double checking the results and reporting this. This looks like a bug. I checked the source code and it seems I have calculated the % of time instead of the % of area for sDA.

This is a major bug and I’ll try to fix it as soon as I can. We should have a new release soon to address this issue.

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Hi @mostapha,

it is a pleasure that I can contribute just a little to this fantastic tool!
If I may, since we are talking about bugs, do you mind have a look to the schedule component?
As it is discussed her with @saram, it seems like the this component behavior is a little strange.

It is fantastic that you always improve this tool. Thanks.
Best regards,


4 posts were split to a new topic: Blinds/shades operation in sDA calculation

The original bug in sDA calculation is now fixed. I can’t recreate the issues with the schedule myself. @saram has provided me an example which will hopefully recreates the error. I will discuss the blind state discussion in a separate reply.

@saram, I think in you case the DA values didn’t go lower than 50 so it didn’t change the sDA. From the cases that I have tested the values are changing after changing the schedule.

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Thanks for fixing it. Please let us know when you are applying the shading algorithm to LEED sDA calculation.

Hi @saram, You should follow this topic for blinds operation implementation and share your thoughts: Blinds/shades operation in sDA calculation