Why does increasing the Room's Limit Offset move the bottom of the room above the roof?

[Anonymous]

Hi - In this situation, with a Base Offset = 0 and Limit Offset = 1, the vertical location of the top and bottom of these rooms looks good

If I change the Limit Offset to 3, I expect the bottom of the room to be unchanged, and the top of the room to extend to 3 feet above the level (or to stop at the roof above)

Instead, the rooms flip to having their bottom at the underside of the roof. Why is this? I thought the Limit Offset only affects the computation of the upper boundary of the room.

Thanks for your help

[ToanDN]

I can't answer why without the model but I can suggest you to drag the rooms in the 2nd image down below the roof to fix them.

[barthbradley]

What's the Computational Height of the Level that the Room is originating from set to?  That might explain.  

[Anonymous]

Computation Height is 1.2. I changed it to 0 and changing the Limit Offset
has the same affect.

[ToanDN]

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@Anonymous wrote:
Computation Height is 1.2. I changed it to 0 and changing the Limit Offset
has the same affect.

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Level's Computational Height does not affect how Rooms placed, only their Area calculations.

Are the original rooms changed after you changed Limit offset or are they new rooms that you placed after you changed Limit offset?

[RDAOU]

@Anonymous 

Seems like a roofs bounding property and level issues; however,two question for you for me to understand the situation better:

• Do the following and advise what do you observe (An image would be helpful)
  1. set Computation to 0
  2. set Room LIMIT and BOTTOM offset to 0 
  3. set Rooms Upper Limit to level above

• What type of element are you using for the roof?
  1. Roof by extrusion?
  2. Roof by Face?
  3. Wall by Face?
  4. ...

[Anonymous]

I've posted the model at
https://drive.google.com/file/d/1Nvg5sZ1uX3XGIPOaD6eb5tFh9gelUkQ9/view?usp=sharing

The goal is to get Revit to provide accurate room volumes. I didn't build
this Revit model, I'm just trying to get accurate data out of it.

[RDAOU]

@Anonymous 

You have to replace the model in Place Roof with a Roof: By Extrusion element

Below will be the result

[barthbradley]

I don't know what's going on without digging deeper, but I edited the In-Place Roof and added a thin veneer (extrusion) at the underside of the existing roof extrusion and all seems right as rain now.  Go figure.  

[RDAOU]

Hey Barth welcome back

Nothing is happening...the extrusion you added does not have rounded edges. When rounded, the bounding surface becomes continuous and  rolls over to the top where it meets the top face of the roof.. If one is such a fan of In-Place Components (I am not) and prefer to use a roof element when it is that simple...but doing the following also fixes it (

1. Edit the In-place extrusion >>>
2. Remove the round edges >>
3. Finishing the extrusion and the in-place fixes the Spaces below
4. Add the round edges as Fascia or another extrusion

[barthbradley]

What do you mean "nothing is happening"?  Something is happening on my end, as evidenced by my screenshots above.  

See for yourself. Here's the RVT: 

[RDAOU]

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@barthbradley wrote:

What do you mean "nothing is happening"? 

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Nothing is happening to the original roof...No need to look into the model it is clear what you did in the screen shot. Technically speaking instead of simply fixing the problem of the original one which is basically the rounded rafter cut, you are adding another roof below the existing one (regardless if it is in the same in-place instance or in a separate one) - cause and effect...if your are ok with such approach in fixing things then all is good

[barthbradley]

I’m very okay with the insight I was able to provide to the OP. It seems I helped you to see the light as well.  Judging from your reply in message #8, you thought it was only fixable by replacing the Model In-Place Roof with a Roof by Extrusion.

BTW: that thin extrusion could easily represent the finish layer. In essence, making the Model In-Place Roof a Compound-Layered Assembly.

No need to thank me. You’re welcome. 

Peace be with you, bro

[JasonLLINDNER]

Hi @Anonymous 

I was popping in to post a question and then saw this cherry on top. We had the same issue with a curved model in place floor. The problem turned out as mentioned above by @RDAOU the half circle rafter cuts. Once we removed them it bounded all most of the rooms some kept behaving weird out of nothing so we ended up redoing the Floors by Face. The model in place one kept throwing at us one issue after the other we fix one and end up with another.