Revit 2021: How to freely sketch a room as we do for a ceiling?

[jamal97220601]

ChatGPT said:

Revit 2021: How to freely sketch a room as we do for a ceiling?

I couldn’t figure out how to freely sketch a room as we do for a ceiling.

[acg37]

In Revit, ceilings are system families that allow sketch-based creation because their boundaries define geometry — you need to manually draw where they go. Rooms, however, are not geometry; they’re spatial data that Revit auto-generates based on enclosed boundaries formed by walls, floors, roofs, etc. You can’t sketch a room because it’s not a drawn object — it 'reads' the model and fills in enclosed spaces automatically.

[mhiserZFHXS]

The above is true, but you can draw room separation lines to give yourself some manual control. 

But rooms are meant to be "smart". So if you find yourself drawing separation lines for every single room, you might want to adjust your workflow. 

[jamal97220601]

What I want here is to automatically calculate the volume of the room. However, I need the walls to be included in the volume calculation.

How can this be done?

[mhiserZFHXS]

Is this just for one specific room?

[acg37]

Revit can’t include wall thickness in room volumes automatically. The workaround is to set the walls to Not Room Bounding, then draw Room Separation Lines along the outer wall faces to define the boundary you want, and let Revit calculate the volume from that. But as @mhiserZFHXS says, if it's not only for one specific room it's not a good workflow.

[arq_42]

If you're trying to calculate the gross area, you'll need to use an area plan, where you'll draw the areas by hand (or semi-automatic).

You can then add a calculated parameter in schedules to calculate the volume by multiplying it by the height.

The rooms are only for net area/volume. The only thing you could do with thm is to calculate them up to the axis of the wall, instead of its interior face.

[HVAC-Novice]

You need to re-consider how you define "Room" in your project. If you consider a room to be something different than the usual definition (used by Revit), you should use something different than oob rooms. 

Area are mor flexible but also require more manual work and don't have volumes. But usually what is needed is area (i.e. rentable area, gross area...) and all have varying definitions (includes, shafts, or exclude them, include walls, or not, include corridors, or not  etc.). But all of those are not "rooms". 

Also consider the engineers using "spaces" will start out using your rooms and possibly sub-divide with space separation lines. But if you include the wall in your rooms, it will mess up their design.  

[jamal97220601]

The purpose here is to calculate, within a schedule, the gross and rentable volume of each floor in the building — similar to how we calculate gross or rentable areas — and then sum them up to obtain the total volume of the entire building.

Is this automatically possible in Revit?

I’m aware of the workaround where I can add a field representing the height of each floor and then multiply the area by the height to calculate the volume. However, since both the areas and heights are already defined in the geometry, why do I need to apply this manually to obtain the volume of each floor or of the whole building?

[arq_42]

The program can't be customized by default for all projects.
Perhaps for your project it would be helpful to have the area know its height by level, but perhaps for another project it won't be useful.

In any case, here's a workaround that will make the posterior modifications automatically:

• Create a global parameter of type "Length" for each level. (Lvl1, Lvl2, Lvl3 ...)
• In a working elevation, place a separate dimension between each level and the next one. Link each dimension to the corresponding parameter using "Label."

• Create a project parameter called AREA HEIGHT and assign it to Area category. 
• When you place a gross area on floor area plan, link the AREA HEIGHT parameter to the Global Parameter of the corresponding level. 
• Create an area schedule, where you will create a calculated parameter called VOLUME, wich formula will be "Area×AREA HEIGHT"

• Now you can manage the separation between levels (their relative height) from the global parameters.

  

The areas will read this parameter and update automatically.
Area schedules will be updated accordingly.

I think it takes longer to explain the workaround than to do it.

I share here the file (RVT26)

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@arq_42 wrote:

I think it takes longer to explain the workaround than to do it.

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This works only if you have building with only flat roofs. The moment you get a sloped one and have to calculate volume underneath it, it's no loner a valid solution.

EDIT: Also, Areas are strictly 2D, you can't display them in sections i.e. you can't create volume drawings (which are required by municipality). You can, by manually placing filled regions.

[arq_42]

Of course! That's why I said the program can't work OOB for all cases; you always have to find a way to adapt it to your project.