Revit 2026: Working with Toposolids – Part 2

by John Flanagan

continued from Part 1

Introduction

In Revit, the site around a building is represented by a toposolid element.

A Toposolid is a 3D component that represents the shape and elevation of the site model in Revit with integrated features such as structural layers, hosted elements, cut geometry, and grading regions.

You can create a toposolid by sketching a boundary and adding elevation points, or by importing data from external sources. You can also convert existing toposurfaces to toposolids.

There are seven types of toposolids in the Type Selector from which you can choose.

Create a Toposolid

Method 1 – From Sketch

The visibility of toposolids may be turned off in floor plan views, so first, open a site view.

For clarity, go to Visibility Graphics and turn off the visibility of primary and secondary contours.

On the Massing and Site Tab, click Toposolid. Choose a type of toposolid form the Type Selector. Use tools on the Draw panel to sketch the closed boundary of the toposolid. In this case we will draw a rectangle. Click Finish when the boundary is complete.

Next click Modify Sub Elements to alter the elevation of the points and edges creating the boundary. Select the edge on the left side and use the in-canvas control to raise it to 6000. Select the edge on the right, use the control on the ribbon to raise the elevation to 1000 and press Enter.

Add Points

Next add points to shape the toposolid.

Click Add Point. Choose to add points along the surface with an offset, or by an absolute elevation measured from the selected datum. In this example place contour elevations based on the Current Level. Set the elevation as you place the points representing the contours of the site as shown below. Click Modify to complete the toposolid.

In Visibility Graphics turn on the visibility of both Primary and Secondary contours.

You can now see the contours displayed on the toposolid.

3D View of Toposolid

The layers making up the toposolid are controlled by changing the structure of the toposolid and are visible when the toposolid is cut, like in a section view.

Section View of Toposolid

Toposolids can be cut with other elements such as a wall, foundation, or void mass elements.