The New Site Ribbon:

HERE ARE 10 THINGS YOU NEED TO KNOW ABOUT THE NEW TOPOSOLID

1- WHAT HAPPENS TO OLD TOPOSURFACES WHEN YOU UPGRADE A REVIT FILE?

If you upgrade a Revit file to Revit 2024, any legacy topographies will remain unchanged but will no longer be editable. To edit them, you'll need to convert them into a Toposolid by selecting the Toposurface and using the 'Generate Toposolid' command on the Modify ribbon.

Keep in mind that generating a Toposolid will cause any building pads to be deleted, as there are no Building Pads in Revit 2024. It's also worth noting that the old Toposurface will remain in place after the conversion. However, it’s recommended to keep the old surface in the project to make sure the conversion results are accurate.

2- HOW TO CREATE A TOPOSOLID?

To create a Toposolid, you can sketch a boundary similar to how you would create a Floor. Once the boundary is complete, you can add elevation points by selecting the Toposolid and using the ‘Shape Editing’ commands in the Modify Toposolid ribbon.

It's worth noting that you can still create a Toposolid from a CAD or CSV file like before. A useful improvement in Revit 2024 is that surfaces created from CAD files can now have a concave boundary, which eliminates the need for additional splitting that was required in the previous version.

3- EVERYTHING IS RELATIVE, ESPECIALLY THE ELEVATION POINTS

In Revit, Toposurfaces only allow elevation points to relate to the Internal Origin point, whereas the new Toposolid allows points to relate to the connected level, Survey Point, Project Base point, or Internal Origin. When creating a Toposolid from a CAD file, the elevation will be absolute and relate to the internal origin point. Keep in mind that a Toposolid behaves like a Floor with a Variable Material, meaning that it can't have a negative elevation below its base. To achieve an elevation below the base, the Toposolid must have a thickness greater than that negative elevation height. For example, to achieve a point at -5 elevation on a Toposolid at elevation 0.00, the surface type would need to have a thickness of at least 5.1.

4- NO MORE SITE SETTINGS - CONTOUR SETTINGS IN THE TYPE

The site settings menu in Revit was previously difficult to find, located under a small arrow on the Massing and Site ribbon. However, with the new Type-based Toposolid, defining the visibility and increments of contour lines for all the Toposurfaces in the file is much easier. Simply access the line styles and increment settings in the type properties. Use the "Object Style" menu to change the color and patterns of contour lines throughout the project, or use the "Visibility Graphic Overrides" menu for specific views. However, keep in mind that contour lines cannot be seen in edit mode, so this may pose a challenge for site design projects.

5- SO MANY NEW CUTTING CATEGORIES (YEY!)

Another major improvement for modeling is the ability to cut into a Toposolid using the "Cut Geometry" option in the "Modify" ribbon, and the best part is that there are many new categories available to use. This means that modeling is now much more flexible. The categories available for cutting include Toposolid, Ceilings, Floors, Slab Edges, Roofs, Facia, Gutter, Roof Soffits, Structural Foundations, Walls, Wall Sweeps, and Mass Void From. So, if you're looking to model a tunnel or a roof garden, this new feature will come in handy.

6- NO MORE BUILDING PADS FOR BETTER OR FOR WORST

Toposurface is not the only element we say goodbye to. The Building Pad element is also being retired, which may be bad news for those who loved it. However, you can still achieve similar results using a simple mass to cut into the solid, although with less flexibility. Unfortunately, there is still no solution for building areas that are above the existing surface and needs to be filled. On the bright side, the new Void form now offers the ability to create sloped edges that cut down into the ground. 

7- NO MORE ‘SPLIT SURFACE’ - THE FAMILIAR ‘SPLIT’ TOOL WORKS ON TOPOSOLID (OMG)

One of the best features of the new Toposolid in Revit is that you can now freely cut and split it using the "Split" tool in the "Modify" tab - this is definitely one of my favorite things about the update! However, keep in mind that once you split a Toposolid there is no Merge option like there was with the Toposurface.

8- SUB-DIVISION INSTEAD OF SUB-REGION

As the Toposurface gets retired from Revit, so does the Sub-Region element. However, we now have the Sub-division command as a replacement. Sub-divisions are like another Toposolid that drapes over the existing one, but unlike the Sub-region, it can't be at the same elevation as the original surface. It needs to have a minimum thickness of at least 1/128 inches (0.2mm), so it cannot have a negative value assigned to it. I must admit, as a landscape architect, this feature can be a handy bonus when working on small-scale residential projects; however, I find it a bit pointless for larger models.

9- TURN OFF POINTS WHEN NOT IN EDIT MODE FOR BETTER PERFORMANCE

This is a nice one if you work with complex surfaces which is common in site design projects.

By default, toposolid points won't be visible when you hover over them, unlike how Floors work. However, if you need to see the points all the time, you can easily turn on this option by clicking the small arrow on the Shape Editing panel.

10- THE NATIVE CUT/FILL FEATURE CHANGES THE CALCULATION METHOD

First of all, it's important to note that you shouldn't rely on native cut and fill values for separated Toposolid elements.

In previous versions of Revit, when you created a new Toposurface, it provided an accurate grading information for each design element, regardless of its shape and material (see the example shown in the picture below).

However, in the new Toposolid, this behavior has changed, which may lead to significant discrepancies with the grading that actually happens on the site during construction.

Instead of calculating the volume difference between the top faces of the existing and proposed surfaces, the feature now uses a Boolean operation to calculate the actual difference between the two solids (since now the existing ground is also solid, with its own thickness depending on the used Toposolid type). While the Boolean operation method allows us to calculate the cut volume in cases such as an underground structure, which wasn't possible before, this method was not designed for site grading.  

The Toposolid feature is finally here in Revit, and while it's a great step forward for site design, there's still some functionality missing.