Operation in Revit



  1. Learn what are masses in Revit
  2. Learn how to work with masses and create geometry
  3. Learn how to create constructive elements from masses


  1. User will be using Revit, any version
  2. User has basic skills in Revit Modelling
  3. User has basic notions about geometry


Masses are a particular category in Revit. It is independent from other categories from objects, and usually is a hidden category By default in views.

Although mass objects are three-dimensional, they do not have a constructive sense as other categories have. They are just geometry.

You can use massing objects to perform a variety of tasks, always in early phases of designs:

  • Create in-place or family-based mass instances.
  • Create mass families that represent the forms associated with often-used building volumes.
  • Vary materials, forms, and relations between masses that represent major components of a building or development.
  • Abstractly represent phases of a project.
  • Study zoning compliance, both visually and numerically, by relating a proposed building mass to the zoning envelope and floor area ratio.
  • Assemble various complex masses from a library of predefined mass families.
  • Generate floors, roofs, curtain systems, and walls from mass instances with control over element category, type, and parameter values. Fully control regeneration of these elements when the mass changes.


You can create masses within a project (in-place masses) or outside a project (loadable mass families).

  • In-place masses are used for mass forms that are unique to a project.

Go to Massing&Site Tab > In place Mass

  • Loadable mass families are typically used when you will be placing multiple instances of the mass in a project, or when you will use mass families in multiple projects.

        To create a Mass Family go to Revit main menu > New Conceptual Mass


Both ways use the same logic to create geometry, and are suitable to create:

  • Just plain geometry
  • Roofs, walls, curtain systems face based.
  • Insert external geometry in other formats.

To create in-place masses and loadable mass families, you will have to use the conceptual design environment.

1 Create geometry

Go to Massing&Site Tab > In place Mass, or

Revit main menu > New Conceptual Mass

In the conceptual environment we do not find the “Geometry Tools” buttons (such as Extrusion, Sweep, Blend, etc.) as we would in family environment. However the “Create form” tool uses the same logic as those specific tools.

For different data inputs we will get different results. Data inputs for geometry in conceptual environment are points, model lines and reference lines, placed in the correct workplane.

1.1 Data Inputs

For different data inputs:

  • Closed lines loop > We get a surface or an extrusion
  • Path and cross section profile > we get a sweep
  • Path and various cross section profiles > we get a sweep blend
  • Two parallel  but different profiles > we get a blend
  • An axis and a profile > we get a revolve
  • We can get same solid and void forms and make boolean operations.

1.2 Model lines vs. Reference lines

What is the difference between choosing Model lines / Reference Lines?:

  • Model lines: They are actual lines or edges that will appear in the model when the family is loaded into the project.
  • Reference lines: They are reference elements that have no graphical visualization when loading or creating the mass in the model, but are a good basis to create geometry. Besides they have four associated workplanes, two intersect in the longitudinal dimension and define the line. Other two are perpendicular to the line at its ends.

Choose in each case the line that best fits to the purposes of the component.

1.3 Actual geometry

Create then the needed elements: points and lines of reference lines that will be the data input for every piece of geometry that we want to model. And use “Create Form”:

  • Remember that geometry can be solid or void. Combinations of solid and void geometry are used to perform boolean operations.
  • Remember also that when creating a Mass there can be created several pieces of geometry inside the same Mass object. This is special relevant when we want to perform boolean operations with voids.

2 Mass families

When creating a mass family, you can do the following:

  • Define any restrictions and parameters needed to control the geometry. See Families guideline, procedure is the same.
  • Nest other mass families into the mass family that you are creating.
  • Import geometry from other applications into a mass family.

3 Masses in project

In a project, you can do the following:

  • Create an in-place mass.
  • Place one or more instances of a mass family.
  • Join a mass instance to other mass instances to eliminate overlap. As a result, their gross volume and gross floor area values adjust accordingly.
  • Import geometry from other applications into an In-place Mass.
  • Create Roofs, walls, curtain systems face based, both from Mass families and In-place masses.
  • Create a schedule that shows the gross volume, gross floor area, and gross surface area of a mass (both family and in-place).
  • Place mass instances in worksets, assign them to phases, and add them to design options.

4 Model by face

From the different faces of a mass geometry we can create constructive elements like roofs, walls, curtain systems and floors. They will perform as regular roofs, walls, curtain walls and floors in their composition, but the form they take will be always linked to the face they come from.

4.1 Curtain System / Roof / Wall by face

Massing&Site tab > Curtain System / Roof / Wall

We select the tool, and then we pick the face we want to convert into one of these three kind of elements.

Notice that:

  • We will be able to convert a whole faces, not a portion of it.
  • For sensibly vertical faces you could be able to create walls / curtain systems.
  • For sensibly horizontal faces you could be able to create roofs / curtain walls.
  • If the mass changes the elements can be updated to meet again the form of the face.

4.2 Floor by face

First create the mass floors. They are the intersection between the mass and the project levels:

Select the mass > Mass Floors

Then you can already use the Floor by face tool:

Massing&Site tab > Floor by face

4.3 Update to face

When we have created elements by face and the base mass changes, those elements will not automatically update their form. This action has to be performed consciously.

Select the element > Update to Face.

Keep in mind that this option will not be valid if the geometry in mass is completely removed and rebuild. It will only work if the geometry is just edited, but not deleted.

It is impossible to re-associate an element-by-face to a face different to the one from which the object initially  (roof/wall/curtain system) was created.


  • By default Masses are hidden in views.
  • Mass geometry is associated to workplanes, both in mass families and in-places masses (levels and reference planes in project)
  • You can add also parameters in in-place masses as you would in mass families.
  • Remember that when you copy an in-place mass it will become a totally different object with no association to the original. Try to use them sparingly.


Masses are a powerful tool in early stages of projects. They allow the designer to check the initial proposals in terms of area, volume, and associated costs.

They are also very useful to create complex geometry where native basic elements are suitable tools for the wanted results.

Associated Files

  • Parameters Guideline
  • Families Guideline
  • Adaptive Component Guideline

Leave a Reply

Your email address will not be published. Required fields are marked *