How to edit Room Boundary in Revit

There are moments when Rooms in Revit do not always show up the way you want them to. There are several ways to edit the room boundary in Revit, to redefine the room areas. Maybe you have a shaft inside a bedroom and don’t want the area of the shaft to be removed, or maybe you want to indicate a kitchen area in the living room without creating walls.

It is good to know that Revit has a built-in parameter and Room Separation Line to create and edit the room boundary. This means we can redefine the measured areas inside rooms.

In this article, I will explain which elements in Revit can be used to define a room boundary. How to check what elements are bounding, and how to edit a room boundary.

Boundaries and Computations

To understand how Revit calculates room areas and volumes, it’s good to know which elements in Revit are room-bounding by default. The boundaries of a room will define how Revit will compute the area and volume.

By default, the following system families are room-bounding:

  • Walls (standard, curtain, face-based)
  • Roofs (standard, face-based)
  • Floors (standard, face-based)
  • Ceilings (standard, face-based)
  • Curtain systems
  • Room separation lines
  • Building pads
  • In-place components (Walls, Roofs, Floors, Ceilings)

By default, the following loadable families are room-bounding:

  • Columns (architectural, and structural only with material set to concrete)

Computation Settings

Rooms in Revit are subdivisions of spaces within a building model and can be seen as a 3D object with information, such as the Area, Perimeter, Volume, etc (read-only parameters).

computation settings revit

It is possible to change the settings on how Revit should measure the room area and volume. In order to change these settings, you need to go to the Room & Area panel.

  1. Open the Architecture tab
  2. Go to the Room & Area panel > Click on the drop-down menu (black triangle)
room and area settings
  1. Click on Area and Volume Computations > Area and Volume Computations menu will open
  2. Change settings for the Volume Computations
  3. Change settings for the Room Area Computation
area and volume computations
area and volume computations

In the first tab with Volume Computations, you can choose whether Revit has to calculate Areas or both Areas and Volumes. As it says in the picture the Areas only is faster to calculate for Revit, so this is a recommended setting. If you also need volumes to be calculated, choose Area and Volumes. Volumes will be calculated at the finish faces of elements at all times.

In the second tab with Room Area Computation, you can choose at which part of the wall the area should be measured (finish, center, core layer, or core center). By default, At wall finish is set by Revit. This is also the recommended setting because this will measure the usable floor area within your model.

Computation Height

Revit also has a somewhat hidden parameter to set the Computation Height. This setting is the distance above the level that is used to compute room perimeter and volume. For example, when a model contains sloped walls, and roofs you can alter the computation height to get more accurate perimeter calculations for the room elements.

The Computation Height is by default 0(mm) above the base level of a room. To change this Computation Height, open an Elevation or Section and follow the steps below.

  1. Click on the level you need to set the Computation Height
  2. In the Properties browser go to the Computation Height > enter the value you need.
set computation height in revit

After the Computation Height is changed you can notice the difference in how Revit calculates the area and Volume.

computation height in revit
Computation Height 0mm
computation height in revit
Computation Height 1500mm


If you get rooms like in the picture below, then make sure to change the Volume Computations from Areas only (faster) to Areas and Volumes. Then it will calculate the volumes again.
computation height in revit

Room Boundary

Now that is it clear what settings you can change, we can take a look at how we can recognize which elements are set to room-bounding and which are not room-bounding, inside the model.

Wall elements are by default Room Bounding (except for Retaining Wall types). This means that you can’t change the parameter before it is placed physically inside your model. Nonetheless, you can change it afterward. For floors, roofs, etc you can change it before and after placing it inside the model.

All these different types of elements contain the Room Bounding parameter that can be found in the Properties browser under the group: Constraints.

edit room boundary in revit

Highlight Boundaries

Revit has a built-in function to check which elements are set to room bounding inside the model, this function is called Highlight Boundaries. To call this function, take a look at the steps below.

  1. Open the Architecture tab
  2. Go to the Room & Area panel > Click on Room
hightlight room boundary in revit
  1. Inside the Modify panel > Click on Highlight Boundaries
hightlight room boundary in revit

Notice that the elements that are set to room bounding will get highlighted by a color you have set in the general options of Revit, by default it’s orange (RGB 000-059-000).

hightlighted room boundaries

Edit boundaries

When placing Walls the room bounding is set automatically to “Yes”. For example in the picture below you can see a bedroom with a built-in closet. The Walls around the closet are room-bounding and prevent the space inside the closet from being included in the bedroom area.

It is of course possible to give both areas a room, but what if you want the closet to be measured with the bedroom area together? To edit the room boundary in Revit, follow the steps.

  1. Click on the elements (Walls, Floors, Roofs, etc) you do not want to be room-bounding
  2. Go to the Properties browser > Room Bounding Parameter > Unmark to “No”
edit room boundary in revit

After the Room Bounding parameter is set to “No” move away your cursor from the Properties browsers to apply the settings, or manually press apply inside the browser. Now notice that the calculation of the Room is changed.

edit room boundary in revit

Room Separation

What if you want to create Rooms inside an open-plan area? For example, do you want to indicate a kitchen area inside your open living room, or maybe you want to indicate a balcony that is surrounded by railings? In both examples, you do not want to use walls that will make the boundary. For these scenarios, we can use the Built-in function of Revit which is called the Room Separator.

Room Separations are lines that act as a room-bounding element. This means that the lines form a boundary to the room. The style of the Room Separation can be modified in the Line Styles settings, check this article.

  1. Open the Architecture tab
  2. Go to the Room & Area panel > Click on Room Separator
room separation line
  1. Inside the Draw panel choose an option to draw the lines (I use the straight line option)
  2. Draw the Room Separation lines inside the view and make sure they close the area.
edit room boundary with separation line

After placing the Room Separator, you can add the Rooms and notice that the Kitchen area is separated from the Living Room area.

edit room boundary in revit


If you’re looking how to Tag Rooms in Revit, I suggest checking out this helpful article: How to use Room Tags in Revit.

Wrapping up

Room areas do not always show up the way you want them to. Revit has some functions to refine how the rooms get calculated, this can be done with the Room Bounding parameter or Room Separation line. Also, it’s worth checking the settings for the different Computations inside your project.

Keep in mind that the rooms in Revit always require elements that are room-bounding to enclose the area.

I hope you found this article useful, if you have any questions then just drop a comment below.

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