Massing represents a building as solid volumes before it has walls, floors and roofs. At concept stage a mass gives floor area, volume and envelope area at once. Once a scheme is chosen, the faces of the mass become the basis for real building elements.
This article covers Revit massing in Revit 2027 through one example, a 30 × 20 m, three-storey office block: building the mass, dividing it with Mass Floors, scheduling the areas, creating walls by face and updating elements when the mass changes. Architectural modelling is taught in full in the Revit Architecture course.
When to use massing in Revit
Massing suits schemes whose shape is still changing and that need overall figures quickly: floor area per storey, total floor area and volume. From those you get site coverage and floor area ratio to check against planning limits. Once a scheme is stable, drawing walls and floors directly, as in walls in Revit, is quicker.
According to Autodesk's help, there are two kinds of mass (Autodesk: About Masses and Mass Families).
| Kind | Created where | Use when |
|---|---|---|
| In-Place Mass | Inside the project | A form unique to the project, used once |
| Mass family | A separate file, template Mass.rft | Placed many times, or used in several projects |
A mass family is started from File › New › Conceptual Mass with the Mass.rft template, then loaded into the project and placed with Place Mass. Families in general are covered in what a family is in Revit.
The Massing & Site tab in Revit 2027
All mass tools are on the Massing & Site tab.
| No. | Panel | Used to |
|---|---|---|
| 1 | Conceptual Mass | Toggle mass display, create in-place masses, place mass families |
| 2 | Model by Face | Create curtain systems, roofs, walls, floors and toposolids on mass faces |
The first button in panel 1 changes its label with the display mode. Show Mass by View Settings shows masses according to each view's Visibility/Graphics settings. Show Mass Form and Floors shows masses and mass floors in all views, even when the Mass category is off (Autodesk: Control Visibility of Mass Instances).
Revit massing example: a 30 × 20 m office mass
The example uses four levels: L1 = 0, L2 = 3600, L3 = 7200 and L4 = 10800 mm. The mass runs from L1 to L4. Creating levels is covered in grids and levels in Revit.
Step 1 — Start an In-Place Mass on the L1 plan
Open the L1 plan and go to Massing & Site › In-Place Mass. The first time, Revit shows the following message.
The last sentence matters: masses do not print or export unless the Mass category is made permanently visible in the view's Visibility/Graphics dialog. Click Close, type a name in the Name dialog, for example OFFICE MASS, and click OK. Revit switches to the mass editing environment with a Create tab.
Step 2 — Draw the boundary with Line and typed lengths
On the Draw panel, choose Line. Click a start point, move right and type 30000, Enter. Continue down and type 20000; left, 30000; up, 20000. Chain is on by default in the options bar, so the segments join.
Typing lengths is more precise than Rectangle, which only lets you click two corners and fix the dimensions afterwards.
Step 3 — Create the solid with Create Form
Window-select all four boundary lines. Properties showing Lines (Mass) (4) confirms the selection. Click the arrow under Create Form on the Form panel.
Choose Solid Form. From one closed boundary, Revit extrudes a vertical solid with a default height of 10,000 mm. Click Finish Mass to leave the editing environment.
Step 4 — Bring the top of the mass to L4
The mass is 10,000 mm tall, 800 mm short of L4. Do not edit the temporary height dimension directly. In the example, editing it made Revit move the bottom face below L1 instead of raising the top.
The reliable way is Align:
- Open an elevation, such as South.
- Type
AL. - Click the L4 level line first.
- Click the top edge of the mass. The top moves up to L4.
The top of the mass now coincides with L4 and shows a lock symbol. When L4 moves, the mass height follows.
Step 5 — Read the mass figures in Properties
Select the mass. The Dimensions group in Properties gives three overall figures.
The example mass has a Gross Volume of 6480 m³, exactly 30 × 20 × 10.8. The Gross Surface Area of 2280 m² is the bottom and top (2 × 600 m²) plus four vertical faces (100 m × 10.8 m). Gross Floor Area is empty because the mass has not been divided into floors yet.
Revit mass floors: dividing storeys and floor areas
- Select the mass.
- Click Mass Floors on the Modify | Mass tab, or the Edit button next to Mass Floors in Properties. The dialog lists every level in the project.
- Tick the levels to divide at, all four in the example, and click OK.
Revit creates only three mass floors, at L1, L2 and L3, and Gross Floor Area becomes 1800 m². Autodesk's help explains that a level at the top face of the mass gets no mass floor, because there is no volume above it (Autodesk: About Mass Floors at the Top of a Mass). So there is no need to be careful about unticking the roof level.
Scheduling mass floors
- Go to View › Schedules › Schedule/Quantities.
- Type
Mass Floorin the category search; Mass Floor sits under the Mass category. Click OK. - Fields tab: add Level, Floor Area, Floor Perimeter and Floor Volume.
- Sorting/Grouping tab: sort by Level and tick Grand totals.
- Formatting tab: select Floor Area and set Calculate totals; do the same for Floor Volume.
- Click OK.
Schedules in general are covered in schedules in Revit.
The schedule gives the area of each storey and the total, and two planning indicators follow directly. Assuming a 1500 m² site: site coverage = 600 / 1500 = 40 %, floor area ratio = 1800 / 1500 = 1.2.
Model by face: walls, floors and roofs on mass faces
The Model by Face panel turns mass faces into real elements. To create walls on mass faces:
- Open a 3D view showing the mass.
- Go to Massing & Site › Wall. Revit starts the wall tool in face-picking mode.
- Pick a wall type in Properties. The Location Line defaults to Finish Face: Exterior, so the outer face of the wall sits on the mass face.
- Click each vertical face of the mass. Each click creates one wall.
- Press
Escto finish.
| Tool | What to pick on the mass | Related article |
|---|---|---|
| Wall | A vertical face | Walls in Revit |
| Floor | Mass floors, after Mass Floors has been run | Floors in Revit |
| Roof | A top or sloping face | Roofs in Revit |
| Curtain System | Any face, including curved faces | Curtain walls in Revit |
For Floor, Select Multiple is on by default: pick the mass floors, then click Create Floor on the contextual tab (Autodesk: Create a Floor from a Mass Floor).
Editing the mass: schedules update, elements do not
Select the mass and drag the triangular handle on one face to lengthen it. The Mass Floor schedule updates at once: each storey grows from 600 to 691 m², total 2074 m².
The walls do not follow. The front wall keeps its old length, and the side wall stays inside the mass.
Autodesk's help states that elements created by face do not update automatically when the mass changes (Autodesk: Update Building Elements to Reflect Changes to the Mass). To update a wall:
- Select the wall.
- Click Update to Face on the Model by Face panel of the Modify | Walls tab.
- Revit shows the Exclude Hosts dialog. Click OK.
- The wall extends to the new mass face.
The Exclude Hosts dialog warns that edits to wall elevation profiles and wall joins cannot be preserved during the remake. To keep edits on a particular wall, tick it to exclude it from the update.
Autodesk adds two notes. Walls and floors lose any sketch edits when you use Update to Face. Elements with explicit constraints, such as a wall whose Top Constraint is Up to Level, are not affected by Update to Face.
Common problems with Revit massing
| Symptom | Cause | Fix |
|---|---|---|
| The mass is not visible | The Mass category is off and the button is set to Show Mass by View Settings | Switch to Show Mass Form and Floors, or turn on Mass in VV |
| The mass does not print | The Mass category is off in Visibility/Graphics | Turn on Mass in the view you print |
| Create Form makes no solid | The boundary is open or not all lines are selected | Check the selection count in Properties and close the boundary |
| The bottom of the mass is off the level | The temporary height dimension was edited | Use Align to put the bottom and top faces on the right levels |
| Mass Floors misses a storey | That level is outside the mass or coincides with its top | Check the mass height against the levels |
| Schedule areas differ from the walls | The walls were not updated to face | Select the walls and click Update to Face |
Turning categories on and off in Visibility/Graphics is covered in hiding elements in Revit.
Frequently asked questions
When should I use an In-Place Mass, and when a mass family?
An In-Place Mass for a form unique to one project. A mass family for forms placed many times or reused in other projects.
Do I need to untick the roof level in Mass Floors?
No. Revit ignores a level that coincides with the top face of the mass, so ticking the roof level still gives the right number of storeys.
Do masses appear on printed drawings?
Only when the Mass category is on in that view's Visibility/Graphics. Construction documents usually keep Mass off.
How is massing different from Model In-Place?
A mass belongs to the Mass category, has Mass Floors and works with Model by Face. Model In-Place creates elements in categories such as walls, floors or Generic Models; see model in place in Revit.
In short, Revit massing has three parts: build the mass on the right levels, divide it into floors for areas, then create elements on its faces. Each time the mass changes, the area schedule follows by itself, while walls and floors need Update to Face.