How to Cut Geometry in Revit (Void Extrusion)

The Cut Geometry is a tool that allows you to change the shape of an element by using another element as a cutter.

In previous articles we have covered how to use the Void Extrusion tool to create many regular and irregular shapes (links to tutorials are provided below the steps in the article).

This guide expands on this particular tool by explaining how to cut multiple voids and how to avoid uncut geometry.

Method – Cut Geometry

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.

The cutting element is the one that creates the opening in the target element.

We’ll be using 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, as we will be using the top of the floor as a temporary plane for the base of the void extrusion.

Steps

1. Go to the Architecture tab > Build panel > drop-down Component menu.
2. Click Model In-Place.
3. Select “Generic Models” as a family category.
4. Click OK.

5. Go to the Create tab > Model panel > drop-down Void Forms menu.
6. Click Void Extrusion.
7. In the Work Plane panel, click Set Workplane.
8. Choose Pick a Plane (Shortcut: PK).

9. Left-click the top surface of the floor.
10. In the Draw panel, select a tool for sketching.
11. Sketch one or more profiles.
12. Click Finish Edit Mode.

13. In the Properties palette, set the Extrusion Start and End.
14. Select the void extrusions.

15. In the Geometry panel, drop-down the Cut menu.
16. Click Cut Geometry.
17. Select the cut element.
18. Select the target element.

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.

If the void extrusion is not cutting, select it and make sure the Cuts Geometry is checked and the Void/Solid toggle is set to Void in the Properties palette.

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

To use a target element with multiple cut elements:

1. Click Cut Geometry.
2. In the options bar, check Multiple Cut.

3. Select the target element.
4. Select the multiple cut elements individually.

Learn how to create curved roofs by using voids

To UnCut a geometry or set of geometries, follow the same steps as for the cut geometry, but use the Uncut Geometry feature as shown in step 15.

Mohamed Fakhry

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.