Help with Areas of Windows / Doors (They dont seem to be correct)

Help Developers
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  • Objective: I’m exporting data from Revit, and I’m trying to ensure that the area of a window is correctly calculated and stored in a parameter. However, the area seems to be miscalculated. For example, if the window is 2 meters wide and 1 meter high, I would expect the area to be 2 square meters, assuming that Revit calculates area as width multiplied by height. Is this the correct value to expect, or should I be looking for a different parameter, such as the “geometry opening” area? I’ve noticed the same issue with doors as well.

  • Issue: I believe the issue is that Speckle might be including the area of the window frame sides in the calculation. The area always seems to be larger than it should be, and through some testing, I’ve noticed that when the window’s height and width remain the same but the frame thickness increases, the calculated area increases significantly.

  • Example:

    Window 1.PNG
    Window 1.PNG1864×898 226 KB

    Window 2
    Window 21866×902 176 KB

Numbers in red: One represents Width, Two is Area, and Three is Height.

_Example - Window 1: The dimensions are 1.4 x 1.6 meters. To calculate the area, we multiply 1.4 by 1.6, which gives us 2.24 m². However, the result we’re getting is 3.89 m².

_Example - Window 2: The dimensions are the same, 1.4 x 1.6 meters, so the area should again be 2.24 m². But the result is 7.12 m².

Since the window size remains unchanged and the only difference is the increased frame thickness, we believe the issue might be that the area of the frame sides is somehow being added to the total window area.

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Hi @Eduard_Carbonell , welcome to the forum :smiling_face_with_three_hearts:

The Area quantity you are seeing is from a Revit Parameter - we are not calculating these ourselves, but just retrieving the value that the Revit API has stored inside the parameter set of an element.

If you’d like a more detailed summary of area, we do also retrieve from Revit API the material quantities on an element, which are sorted by material and viewable in dev mode:

image
image730×671 111 KB

This is indicating there is 0.78sqm of glass on the window.

Neither of these will give you the width x height value of the window. I suppose whether or not this is “correct” depends on your definition of area - some Revit API material quantities will give you the area of a single face of an element (if it is a host like a wall or floor) while for other elements like windows, it will give you the total surface area of the element. See this thread on the revit forums for more information: Method GetMaterialArea() appears to use different formulas for computing the area depending on the e... - Autodesk Community

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