I got different values for Window to Wall Ratio (WWR) of the same building geometry using two different approaches ?

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For scenario '1' did you use the SketchUp plugin or did you run a measure. Also did you apply it to the entire building or just specific facades. For scenario '2' did you select SketchUp surfaces that already had windows in them? Also does you model have any plenum or attic zones?

For Scenario 1: I used the Open studio tool/plugin which simulated the sketch up model. I did it floor wise. I deleted all floors but one and assigned the whole floor to one thermal zone and then simulated model to get the WWR in the open studio results section. I did this all floors one by one.

For Scenario 2 : Yes I calculated the surface area of the building model that had already window in them . I calculated it as WWR = window area/(window +wall area). Yes, the building has plenum in it.

Kindly help

Does your model have matched internal surfaces, so that the boundary condition of internal surfaces is 'Surface', instead of 'Outdoors'?

@David Goldwasser : Kindly review my answer to your question which may help you in proving the answer to my original Question.

Thanks

@adhiraj03 the bold comment doesn't result in quicker reply.

1. Per @Eric Ringold's question, if your one zone per floor is made up of multiple spaces assigned to the same zone but not surface matched, you could have a lot of exterior windows.
2. The WWR user script and WWR measure don't currently know to ignore plenum zones (make sure you are not adding windows to the plenum.
3. How are you manually calculating the surface area of the building with windows? If you select a base surface in SketchUp it doesn't include the area of the window.
4. Are you hand drawing windows in Scenario 2.