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Set WWR by facade measure is increasing the area of the windows than what is specified

asked 2021-07-01 16:23:36 -0500

Rwadhwa910's avatar

I am running a model where the baseline model has 27,000 ft2 of exterior wall area in the building but when I run the set wwr measure the area of the wall is increased to 548,790 ft2 although the wwr is maintained at 20% but the wall area is increased by a huge margin.image description

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Something s very different in the models. Top model has 27k m^2 of above ground ext walls (I'm guessing columns based on an HTML I have of that table, would be nice for you to show them) and 9k m^2 of window glass area. At first glance it looked like wall area was close to double until you look a the decimal and see it up near but not exactly 20 x to 549k m^2 of ext wall. Window changes is 12x up to 110k m^2 of glass area. If you look at the MULTI_CLASS some are going from 2k to 82k of ext wall area without floor area change. It is like there a bunch of extra stray copies of walls.

David Goldwasser's avatar David Goldwasser  ( 2021-07-02 14:16:05 -0500 )edit

I would look at E+ warnings for clue. Also saw this tagged as legacy-openstudio, but maybe that was inadvertent?

David Goldwasser's avatar David Goldwasser  ( 2021-07-02 14:17:47 -0500 )edit

*** Incomplete View factors *** ..Incomplete view factors can result from incorrect floor specifications (such as tilting 0 *** ..instead of 180) or not enough surfaces in a zone to make an enclosure. The error message *** ..also shows an enforced repciprocity value. You can decide if you need to make geometry *** ..changes based on that value.

Hi @David Goldwasser, Apart from these warnings I could not see anything related to fenestration. I have attached the error file here.

Rwadhwa910's avatar Rwadhwa910  ( 2021-07-06 09:35:33 -0500 )edit

I don't have time to look at the model, why don't you post a screenshot of it either in Application or SketchUp Plugin. If it can't open in those viewers that is another indication of a problem. Also explain in more details the exact steps between model A and model B. By default the WWR measure won't touch ay base surfaces, there is an option to split non-convex surfaces to add triangular windows, which is an exception, but you can disable that, and I don't see that creating the behavior you describe. It is likely something else was done. Maybe go back and start from the original model again.

David Goldwasser's avatar David Goldwasser  ( 2021-07-07 11:31:52 -0500 )edit

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answered 2021-07-09 22:51:18 -0500

@Rwadhwa910 I think I may have found something in this issue. The problem is not in the measure but in the underlying geometry methods. Work around for now could be to choose Remove Doors for the Exterior Door Logic argument

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Asked: 2021-07-01 16:23:36 -0500

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Last updated: Jul 09 '21