Revit, SketchUp

The Best SketchUp Alternative for Conceptual Design

Beginning on November 4, 2020, SketchUp will no longer offer its Classic Perpetual License with Maintenance and Support.  Instead, SketchUp users are invited to begin a yearly subscription to SketchUp Pro with annual upgrades and support built in.  Not surprising, it comes at a hefty cost for a tool most of us use for quick conceptual design studies.  

If you’re ready to find a program that allows you to create quick concepts without gouging your budget, look to Revit.  It’s likely already in your workflow, so it will not add an additional expense or learning curve.  The native mass-modeling environment is highly powerful once users master its interface.  Additionally, mass models created within Revit can be imported into project files and instantly converted to buildings with parametric walls, floors, levels, and other building elements with the click of a button, regardless of complex mass model shapes.  This saves a great deal of time over creating a mass model within another program and having to re-create the data within Revit once the concept is approved.  Let’s look at how conceptual design in Revit works and how it can increase productivity throughout every phase of your next project.

  1. Open the Conceptual Mass Environment

The conceptual design environment in Revit is a unique modeling environment separate from Revit project files.  Think of it as similar to the way in which families are created.  To enter the conceptual mass environment, select File > New > Conceptual Mass from the Ribbon or, if on the Revit start screen, select New Conceptual Mass under the Families section.  Once inside the mass family environment, the interface will appear as a hybrid between a project and a family file with levels and sketch tools to create solid and void forms.  Files created within the conceptual massing environment will be saved as .rfa Revit family files.

Like the Revit project environment, you will be able to import 3D AutoCAD files to use as the basis of your mass model.  This is especially helpful when modeling existing buildings for which there is already an existing 3D model.  To do this, first simplify your file within AutoCAD to remove unnecessary geometry and linework.  Remember, conceptual mass models exist to calculate floor and site areas or perform energy analyses; design details can be added later.  Navigate to the Insert tab and click Import CAD.  You can insert Rhino, SketchUp, AutoCAD, or ACIS SAT files.  Toggle the settings as needed, being sure to Import as Category: Mass.  Then, select Open. The form will appear in your drawing area exactly as it does in the CAD file.

2. Understand levels, reference points, and reference lines

When you open the conceptual mass environment in Revit, you will see two reference planes and a default level.  Levels within mass models operate as they do in project files.  The default level can be moved or copied to create additional levels at specified heights.  These levels act as planes that can host model elements as well.  

Reference points are useful to create a plane from one point in your mass model or to draw a spline connecting a series of points.  Points can be created by selecting either Model Lines or Reference Lines from the Draw panel of the Modify tab on the Ribbon.  

Reference lines have a range of uses in the Revit conceptual modeling environment.  First, reference lines can be used to create solid or void geometry in much the same way as model lines can.  The difference is that reference lines lock the geometry into place to maintain the shape of the original profile.  The top face can be unlocked, but the shape cannot be shifted away from its base profile.  Additionally, reference lines automatically create reference planes at each end of the line and, for straight lines, along the length of the line.

3. Use sketch tools to create forms

While reference lines are certainly useful, if your form is likely to shift and move away from its initial profile as your concept matures, it is wise to use model lines to create your mass.  The sketch tools within the conceptual design environment work similarly to sketch tools in Revit projects and families.  However, one key difference is that solid and void forms can be created from linework that does not form a closed boundary.  

Once a line or shape is created, the Create Form button on the Modify tab allows you to create a solid or void form from your sketch.  Clicking on any surface or line within the form enables shape arrows that allow you to move your shape in space along the X, Y, or Z axis.  When you move your shape, temporary dimensions will appear that allow you to control its length and height.  Additionally, you can select a face within your shape to change the element from a simple form to a mass floor, interior wall, gridline, etc.  If you wish to add a vertical line to a face on your form, select “Add Edge” on the modify toolbar, or similarly, select “Add Profile” to create a horizontal band. 

4. Constrain with dimensions and parameters

Because mass modeling is often used to determine a building’s area or its footprint within a site, it is important to master the use of dimensions and parameters to constrain the model.  To do this, first create a profile with model lines.  Then, on the Create tab, use the dimension tools to dimension from the model lines to the reference planes.  Select one of the created dimensions and, under the Label Dimension panel of the Modify tab, select Create Parameter.  This allows you to create parameters to indicate a mass building’s distance from the lot line or the overall dimensions of the building, for example.  Multiple parameters can be linked together through formulas to constrain a mass to adhere to certain parameters, such as a maximum lot coverage percentage.

5. Convert to building elements within Revit

Once you have solidified your design within the conceptual building environment, it is time to load it into a Revit project.  There are a few important settings to consider as you prepare your mass family.  First, the levels you create in the conceptual design environment will not translate to the Revit project.  These will need to be created or updated once you are in your project file.  In the Properties palette, uncheck Work Plane-Based so that the model can be loaded into a Revit project without you first selecting a work plane to host it.  Next, open the Revit project file you would like to load your mass into.  Load the mass into your project just as you would a finished family file and click to place it.  The mass will be visible in all views unless you change the settings on the Massing and Site tab.

To create walls from your mass faces, go to the Architecture Tab, and on the dropdown menu under the Wall command, select Wall by Face.  This allows you to choose a wall type and apply it to faces within your mass family.  For users who have not yet upgraded to Revit 2021, this is an efficient way to create slanted walls.

Ready to create a mass model for your next project?  Get step-by-step guidance and support from the experts at Cadnetics U!  We’ll walk you through every step within your own project so that you can learn while producing billable work.  Learn more at

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