Wednesday, January 23, 2019

Room Gap at Open Wall Ends in Revit

Autodesk Revit has a gap tolerance when looking for the boundary of a Room element... but there are rules imposed to maintain model/system performance. As you can see in the first image below, the gap can be quite large; 1'-8" (508 mm) in this example. This post talks about those rules...


Read on to learn more...

In the image above, all four corners have a gap, but the Room element is still enclosed. An unusual condition, but it clearly makes the point that there can be gaps. This is not ideal, but as you read on you will see one common situation where this can occur on a project.
FYI: Spaces, used in place of Rooms by MEP designers, work the same way... you could replace the word Room with Space everywhere in this post.
Notice that the open wall ends have a red dot... I added this to all the 'open wall ends' that are part of the equation in determining if a room is enclosed or not. To be clear, 'open wall end' means a wall with no other wall associated with its end point.

In the next image, below, Revit is still able to clearly find 'open wall ends' within the built-in and hardwired gap tolerance.



But now, in the image image, we have over complicated the boundary and an 'open wall end' is no longer within the gap or positioned in a way that forms a reasonable enclosed area.



Yet another complication is multiple 'open wall ends' within this gap tolerance.



As a mentioned previously, a common case where this might occur on a project is were an interior wall stops short of an exterior curtain wall... especially with the curtain wall is irregular shaped. In the simple example below, as with the first image above, these gaps are easily dealt with by Revit and the Room properly fills the space.



But then you start adding adjacent rooms with shafts and partitions parallel to the curtain wall and things get tricky as seen in the next two images...




In these cases Revit needs a little help. Adding a Room Separation line as shown solved the problem. Use these sparingly and make sure they do not overlap other room separation lines or walls as that will create Revit Warnings and potential cause model performance issues.


Here is one last example, showing an acceptable gap between two 'open wall ends' at an inside corner.


Understanding how Revit works in this situation can help quickly and properly deal with a problem with one arises. Again, these rules are in place to maintain model performance, so Revit is not spinning its wheels all the time trying to verify and re-verify room enclosures during model creating and edits.


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