Revit Massing (Pt. I) : In-Place Mass vs Mass Family

Autodesk® Revit® massing is a powerful tool for generating masses that works at any scale, whether you’re at the conceptual level of a building, at the detailed level refining the fixings and furniture, or working on an entire masterplan. To be able to use this tool to your advantage you should know a couple of techniques. There are two basic workflows for creating masses: create the massing within the project itself (In-Place Massing) or create it in a separate conceptual mass family, which is then loaded into the project. Here’s a brief comparison of these approaches.

In-Place Massing is carried out directly inside the project environment.

Allows you to see the rest of the project context, which is useful when designing at an early stage
The most straightforward approach and works well when the building volumes are not too complex
Good for preliminary sketching of forms and is the recommended approach for early stage design and for conceptual building studies

On the other hand, a Conceptual Mass Family is built in the ‘conceptual massing environment’, outside of the project environment.

Iterations of the family can be placed as needed around the site.
The family can be loaded into multiple Revit models.
Different team members can work on the different versions of the family.
Better for developing and refining a building mass. The separate environment has additional visibility of 3D levels and reference planes which makes more complex parametric modeling easier.

We’ll go into more detail on conceptual mass families in a separate article. For now, let’s look at In-Place Massing more in-depth.

Creating an In-Place Mass

Unless the site has significant changes in levels that would have a real impact on the massing, assume the site is flat and start massing the scheme at ground level.

Make the ground floor plan active.
If using worksets – activate a workset in which the mass is going to be modeled.
Massing & Site > In-Place Mass.
Name the mass, e.g. Block C.
Draw the profile (the base of the mass), selecting the appropriate drawing tool.
Click ‘Create Form’ to give the mass height.
Click ‘Finish’ to create the mass.

* Click to set the mass to the selected 00 Ground Floor level
* Closing the loop saves time in creating the form

* Draw profile using Revit drawing tools
* Mass profile can be drawn on a set work plane or on an existing face (we’re drawing on work plane in this example)
* Mass profiles can be edited at later stages

Adjusting the Height

Open a section cutting through the site or elevation view showing the levels.
Select the solid and use the blue arrows to drag and align the extrusion top to the required level (alternatively, use the Align tool).

Note: Locking the top of the mass to the level means it will adjust if the floor-to-floor levels change; however, it will adversely affect performance.

Note: When you select a mass (any view), you will automatically see blue arrows on each face. Adjusting the form using the arrows is always perpendicular to the face.

Basic Mass Editing: Changing the profile

Select the mass, then click ‘Edit In-Place’.
Tab to select the extrusion (by default Revit will select the face /edge first but tabbing will allow you to select the solid).
Click ‘Edit Profile’.
Select the top or bottom surface (tab if necessary).
Adjust the profile trace line, then accept.
Click ‘Finish Mass’.

* Mass must be unlocked from level in order to edit profile
* Use Revit Offset tool (OF) and tab over the profile line to evenly offset the perimeter

E.g.

Note: If mass has floors, they will be automatically updated to the new profile.

Basic Mass Editing: Changing a face or surface

Select the mass, then click ‘Edit In-Place’.
Select an edge or face of the solid (tab if necessary).
Drag the form along one of the triad axes.

*Press the spacebar to change the extrusion direction: in line with view axes or perpendicular to surface.

Basic Mass Editing: Joining forms

The Join Geometry tool can be used to join one instance of a mass to another. It merges one form into another; if the forms overlap, the second form is adjusted to reflect the correct floor area.

Modify > Join
Select first mass, then the second

Note: Intersection lines are formed where forms are joined.

Note: For the floor to read as one floor plate, the forms need to be contained within a single mass family. If forms are pasted into a single mass family, then the floor becomes a single element.

Basic Mass Editing: Adding voids

You can create voids in the massing using the Create Void form. For this to work, the void must be created inside the mass that you want to cut. Note that adding several voids may slow down file performance.

Select the mass, then click ‘Edit In-Place’.
Select drawing tool.
Set the plane to draw by face or to a work plane.
This will affect how the solid extrudes (see below).
Draw the profile of the void.
Select the perimeter (tab & click).
Click on void form.
Drag the extrusion (press spacebar to orientate
to face).
Click ‘Finish Mass’.

Note: When void base is set to ground plane:

Note: When void base is drawn on face and extruded perpendicularly:

Basic Mass Editing: Multiple forms in a single mass

It is not necessary to create a separate mass for each form. If several blocks form part of the same building and share the same floor level, then they should all be created in a single mass. This makes editing easier and when mass floors are applied, they are treated as a single entity.

In-Place Mass Tip #1: Workflow

Keep in-place massing in a separate project file, so it can be linked as required. Consider breaking the scheme into separate building models with their own mass floors if the floor levels vary significantly.

In-place massing should only be considered for initial master planning where the masses are pretty much straightforward extrusions and where being able to view the context is useful. If the scheme is more complex or you want to create the form multiple times, consider using the more flexible conceptual mass environment and load the conceptual mass families into the project.

In-Place Mass Tip #2: Pick face to host mass

In addition to selecting a level to host the mass, you can also use the pick option to host the mass on an existing face, e.g. a sloped surface.

Note: Enter the mass first, then pick a drawing tool. Set to draw on face or set a work plane manually, and pick any face of the mass and draw a shape (profile) from which you can create a mass or a void (can cut into the mass).

In-Place Mass Tip #3: Keep work orthogonal

Set out the masses using ‘reference planes’ and pin them in place as a guide for the massing. This helps make sure everything is kept orthogonal.

In-Place Mass Tip #4: Reference lines

If your form is likely to change a lot, use reference lines instead of model lines. When the form is deleted, the reference lines remain, allowing the form to be easily recreated.

Conclusion

To summarize, these the principal benefits of using in-place mass families are:

They let you generate schedules and produce other types of data to describe geometry, architecture, or other features of massing.
You can nest other mass families into the mass family that you are creating.
You can import geometry from other applications into the mass family.
In-place mass families work like any other Revit family. Family types and instances are displayed in your project browser.

Revit in-place massing is an especially useful tool for architects. Producing conceptual massing within the context of the project site and then generating elements like walls, floors, etc. upon those masses is a great way to go.

In Part II of Revit Massing we will look at how to create a Conceptual Mass Family outside the project environment.

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