Cut Geometry is the Revit tool that lets one element, usually a void, cut an opening in another element, such as a floor, wall, roof or family. This guide shows how to cut geometry in Revit with a void extrusion, how to cut several elements at once with Multiple Cut, how to uncut geometry, and what to check when a void does not cut. The steps are checked against Autodesk’s Revit help, with a note wherever an older release looks different.
Quick answer
To cut geometry in Revit, go to Modify tab > Geometry panel > Cut drop-down > Cut Geometry, click the cut element (usually a void), then click the target element you want to cut, such as a floor, wall or roof. Revit removes the volume of the void from the target.
To cut several elements with one void, tick Multiple Cut first. To undo a cut, use Uncut Geometry from the same drop-down.
Practice file · .RVT
Follow this guide on the same Revit file
The Revit project (.rvt) from this tutorial and its reference files are on the Mashyo Patreon. Open it beside this page and repeat each cut geometry step on a real model instead of an empty project.
Get the cut geometry practice file
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The Cut Geometry tool changes the shape of an element by using another element as a cutter.
In previous articles we covered how to use the Void Extrusion tool to create many regular and irregular shapes (links to tutorials are provided below the steps).
This guide builds on that tool. It explains how to cut geometry in Revit with a void, how to cut multiple voids and multiple elements, and how to avoid uncut geometry.
How to Cut Geometry in Revit (Void Extrusion Method)
To cut geometry in Revit, you need two elements: a cut element and a target element. Either can be a solid (wall, floor, roof, family, etc.) or a void form with a solid. Autodesk notes that you typically cut geometry with voids, but you can also cut some models with solids, such as conceptual masses and model family instances.
The cutting element is the one that creates the opening in the target element.
We’ll use a solid floor as the target element. Make sure it’s a flat floor and that you have set the correct floor slope before following the steps, because we will use the top of the floor as a temporary plane for the base of the void extrusion.
Steps
- Go to the Architecture tab > Build panel > drop-down Component menu.
- Click Model In-Place.
- Select “Generic Models” as a family category.
- Click OK.
- Go to the Create tab > Model panel > drop-down Void Forms menu.
- Click Void Extrusion.
- In the Work Plane panel, click Set Workplane.
- Choose Pick a Plane (shortcut: PK).
- Left-click the top surface of the floor.
- In the Draw panel, select a tool for sketching.
- Sketch one or more profiles.
- Click Finish Edit Mode.
- In the Properties palette, set the Extrusion Start and End. The void must reach through the full thickness of the target, or it will leave the floor partly uncut.
- Select the void extrusions.
- In the Geometry panel (Modify tab), drop down the Cut menu.
- Click Cut Geometry.
- Select the cut element (the void).
- Select the target element (the floor).
Voila! That’s it.
If you want to use this tool to create cool text and shapes on curved surfaces, check out our post on curved walls.
Void Not Cutting in Revit? Quick Fixes
If the void extrusion is not cutting, select it and make sure Cuts Geometry is checked and the Void/Solid toggle is set to Void in the Properties palette.
Also remember that a void normally affects only geometry that already exists when it is created. To make a void cut solids that were created after it, or any element it missed, use the Cut Geometry tool as shown above. It lets you choose exactly which elements get cut, whenever they were created.
Void checklist
Void set to Void, Cuts Geometry ticked, extrusion Start and End passing through the full thickness of the target, and the cut applied with Cut Geometry if the target was modeled after the void.
Use the Sides of a Floor as a Work Plane
You can also use the sides of a floor as a work plane to model floor transition strips and partitions.
Learn how to cut through terrain using the Toposolid tool
How to Cut Multiple Elements in Revit (Multiple Cut)
To use a target element with multiple cut elements:
- Click Cut Geometry.
- Check Multiple Cut. In Autodesk’s help this checkbox is on the Options Bar; if your release has no Options Bar, look on the ribbon tab that appears while the tool is active.
- Select the target element.
- Select the multiple cut elements individually.
Learn how to create curved roofs by using voids
How to Uncut Geometry in Revit
To uncut a geometry or a set of geometries, go to Modify tab > Geometry panel > Cut drop-down > Uncut Geometry, then select the elements whose cut you want to remove. This removes only a cut applied between two or more elements with the Cut Geometry tool. Press Esc or click Modify to exit the tool.
The workflow mirrors Cut Geometry: the same drop-down you used in step 15, with Uncut Geometry in place of Cut Geometry.
Practice file · .RVT
Now do it once on a real model
Cutting several elements with one void takes two minutes to read and a few tries to get right. The practice file for this lesson gives you the Revit project from this tutorial, so you can run each step yourself and keep the file for reference.
Download the cut geometry practice file
$5.5/month on Patreon. One membership unlocks all 40 Mashyo practice files. Cancel anytime. See the full file library.
FAQs
Where is Cut Geometry in Revit?
On the Modify tab, in the Geometry panel, open the Cut drop-down and choose Cut Geometry. Uncut Geometry is in the same drop-down.
Why is my void not cutting in Revit?
Select the void and check that Cuts Geometry is ticked and the Void/Solid toggle is set to Void. Make sure the extrusion passes through the whole target. If the target was created after the void, apply the cut manually with Cut Geometry.
How do I cut multiple elements with one void?
Start Cut Geometry, tick Multiple Cut, select the void, then click each element you want it to cut one at a time.
What can a void cut in Revit?
Typically walls, floors, roofs and ceilings, plus model elements such as structural framing, columns, foundations, casework, furniture, specialty equipment and generic models.
How do I undo a cut geometry in Revit?
Use Modify > Geometry > Cut drop-down > Uncut Geometry and select the cut elements. This removes the cut without deleting the void.
Is there a Revit practice file for this tutorial?
Yes. The Revit project file for this lesson is available to Mashyo members on Patreon for $5.5/month, together with the practice files for the other Mashyo tutorials. You can cancel at any time. Open the cut geometry practice file on Patreon.
Mohamed Fakhry has helped thousands of architects and designers find their next project with step-by-step guidance on his blog, mashyo.com. About Mohamed
His journey began during his university years when he recognized the need for information-rich 3D models to accelerate learning and improve production processes. Now, Mohamed shares his expertise through Revit tutorials that are accessible to all.
