Working with Toposolid in Revit means unlearning most of what the older tutorials teach. The Toposurface tool is gone from the 2027 release, and what replaced it is a different kind of object altogether.
This article runs from that change through to a site plan fit for a planning submission. To learn modelling and documentation end to end, see the Revit Architecture course.
What the 2027 release removed, and what replaced it
Release 2027 no longer has Toposurface, Site Settings, Split Surface, Merge Surfaces, Building Pad or Subregion.
An old file built with Toposurface still opens on 2027 and can still be edited at a basic level. But the tool to create one is gone, so every tutorial still teaching Edit Surface and Place Point is out of date.
The new terrain object is the Toposolid. The name says what it is: a solid, not a surface. It has real thickness, a real volume, and a layer structure like a wall or a floor.
Anyone comfortable with floors has almost nothing new to learn, because sketching and reshaping work identically, as covered in how to create floors in Revit.
| Tool | What it is for |
|---|---|
| Contextual Data | Loads context data from an online map service. Needs an account and a connection |
| Toposolid | Creates terrain. The main tool of this article |
| Site Component | Places trees, vehicles, people and other site entourage |
| Parking Component | Places parking bays |
| Property Line | Draws the plot boundary |
| Label Contours | Writes elevation values onto contour lines. Greyed until the project has terrain |
Create terrain in Revit: six types and the solid properties
The Toposolid button offers two routes. Create from Sketch draws a boundary by hand and then reshapes it, for a flat plot or one with only a few measured levels. Create from Import builds from a survey file, for a 3D survey drawing or a point file.
| Type | What it is |
|---|---|
| Generic - 1000mm | A generic solid 1 m thick with no material. For trial modelling |
| Grassland - 1200mm | Grass 1.2 m thick. The default, used for natural ground |
| Path - 150mm Wood Planks | A boardwalk path 150 thick |
| Path - 350mm Asphalt | An asphalt path 350 thick |
| Path - 350mm Concrete | A concrete path 350 thick |
| Water - 2000mm | Water 2 m thick, for ponds and pools |
The three Path types make paths and yards separate solids laid over the grass, each with its own layer build-up.
| No. | Part | What it does |
|---|---|---|
| 1 | Constraints group | Level, Height Offset From Level and Room Bounding. Terrain bounds rooms just as walls and floors do |
| 2 | Dimensions group | Perimeter, Area, Volume, Elevation at Top, Elevation at Bottom and Thickness |
Elevation at Top and Elevation at Bottom are the most telling boxes. While the terrain is flat they show a figure. Once it slopes they read varies, meaning the height differs from place to place.
The Volume box matters too. Terrain in 2027 has a real volume, so it can be scheduled, which the old surface could not. Autodesk describes the object on Toposolids.
Reshaping terrain: Add Point and the Absolute mode
Select a terrain solid and the ribbon opens a contextual tab carrying the main toolset.
| Tool | What it does |
|---|---|
| Edit Sketch | Returns to sketch mode to change the outline |
| Modify Sub Elements | Select a vertex or edge and type a new elevation. The main reshaping tool |
| Add Point | Adds an elevation point inside the solid, the way survey levels are entered by hand |
| Add Split Line | Adds a crease, for a ridge or the edge of an embankment |
| Pick Supports | Uses other elements as supports so the terrain follows them |
| Reset Shape | Returns the solid to flat, removing every added point and line |
| Sub-divide | Defines a region inside the solid. This is what replaced Subregion |
| Simplify Toposolid | Reduces the point count when imported terrain is too heavy |
| Excavate | Uses intersecting geometry to cut the terrain. This is what replaced Building Pad |
The first six match the floor shape-editing tools exactly. As promised: learn floors and you know terrain.
Click Add Point and the ribbon adds one more panel, and that panel decides what the number you type actually means.
| Mode | What it does |
|---|---|
| Along Surface | On by default. The new point is offset from the existing surface by the Offset from Surface value |
| Absolute | The new point sits at the true elevation typed in the Elevation box. This is how survey data is entered |
| Snap XYZ | Snaps to a point that already exists in the model |
| Elevation Base | The datum for elevations, Project Base Point by default |
Entering a set of survey levels takes five steps. Step 3 is done once; the others repeat for each point.
- Select the terrain and click Add Point.
- Click Absolute on the Modifier Elevation panel.
- In the Elevation Base box, choose Survey Point if the survey levels refer to the national datum. Keep Project Base Point when they refer to the project datum.
- Type the elevation in the Elevation box and press Enter.
- Click the position of that point on the plan.
As soon as two points differ in height the terrain slopes and contour lines appear. The full sequence is on Create a Toposolid by Sketching.
Revit contour lines: where the interval lives now
This is where the change from the old release shows most. The old one set the contour interval once for the whole project in Site Settings. Release 2027 sets it per terrain type, in Type Properties.
| No. | Part | What it does |
|---|---|---|
| 1 | Construction group | Structure opens the layer dialog, exactly as for walls and floors. Default Thickness is greyed because it is the sum of the layers |
| 2 | Graphics group | Coarse Scale Fill Pattern, Coarse Scale Fill Color and Contour Display, the row that replaced Site Settings |
Setting it per type is an improvement. Natural grass can carry a contour every metre while a concrete yard carries none at all. The old release could not separate the two.
| No. | Part | What it shows |
|---|---|---|
| 1 | The two default rows | Row one is the primary contour at 1000, row two the secondary at 500 |
| Column | What it does |
|---|---|
| Start and Stop | The elevation band the rule applies to. The wide default suits any ordinary building |
| Interval | The contour spacing. The box that most often needs changing |
| Range Type | Multiple Values draws a series at that spacing; Single Value draws one line at one elevation |
| Subcategory | Primary Contours for main lines, Secondary Contours for intermediate ones, each with its own line style |
The 1000 and 500 defaults suit a large, steep site. On a flat house plot of a few hundred square metres no contour appears at all, which is why many people assume the tool is broken.
The rule for choosing is simple: take the greatest height difference across the site and divide by about ten. A 2 m fall wants a 200 interval; a 20 m fall wants 2000. Fewer than ten lines looks empty, more than twenty looks cluttered. Autodesk covers the dialog on Control Contour Display on Toposolids.
| No. | Part | What it shows |
|---|---|---|
| 1 | Elevation point | One of the two points added with Add Point, at the end of the innermost segment |
| 2 | Contour line | Closed rings wrapping the two high points; each ring outwards is lower |
| 3 | Terrain boundary | The outermost rectangle, the outline drawn in sketch mode |
Contours without values tell the reader nothing. Label Contours adds them: draw a line across a group of contours and Revit writes the value at each crossing.
Sub-divisions, the Revit property line and excavation
Concrete yards, planters, water and paths are all regions with a material other than grass. Sub-divide handles them: select the terrain, run the tool, then sketch the region. It follows the host elevations but takes its own type and material.
Raised paths and thresholds are different: they need their own heights, so draw a separate Toposolid laid over the host.
The plot boundary is compulsory on any site plan for a planning submission. It is not an ordinary line but a distinct object carrying survey data.
| No. | Part | What it holds |
|---|---|---|
| 1 | Deed Data table | Seven columns: Distance is the side length; N/S and E/W the quadrant; Bearing the angle; Type is Line or Arc; Radius and L/R for arcs |
Below the table, From last to first point reports whether the boundary closes. An open boundary means Revit cannot compute the plot area.
Bearings are written in quadrant form, so N 45° 00' 00" E means 45 degrees from north towards east. Local land records often quote a whole-circle bearing from 0 to 360 degrees, so convert before typing.
A building with a basement or a floor below natural ground has to be dug in. The old release drew a separate Building Pad; 2027 uses Excavate, taking the building element itself as the cutter so nothing extra is drawn. Leave terrain sitting over a floor without excavating and Revit warns that toposolid and floor overlap.
Cut and fill Revit reports: Graded Region and the Cut and Fill boxes
Revit calculates earthwork for you. It compares two terrain solids in two phases: the earlier one is the existing ground, the later one the graded surface. The Graded Region tool builds that pair.
- Select the terrain. In Properties, set Phase Created to Existing.
- Open the Site view. Check that the view's Phase in Properties is New Construction.
- Go to Massing & Site › Modify Site › Graded Region.
- The dialog offers two choices. Pick Create a new toposolid exactly like the existing one to keep every elevation point.
- Click the terrain. Revit marks the original as demolished in the current phase and creates a new copy in that phase.
- Reshape the copy to the designed levels with Modify Sub Elements or Add Point. Click Modify when done.
- Select the copy and read three boxes in Properties.
| Box | What it means |
|---|---|
| Cut | Soil removed, where the new surface is lower than the old one |
| Fill | Soil added, where the new surface is higher than the old one |
| Net Cut/Fill | Fill minus Cut |
The figures are approximate, typically within 1–2%. The volume is counted only inside the boundary of the new solid. Autodesk explains the calculation on About Reporting Cut and Fill Volumes on a Site and the steps on Create a Graded Region.
Soil dug out for a basement with Excavate is read elsewhere. Select the terrain to read Total Excavation Volume. Select the floor used as the cutter to read Excavation Volume on Toposolid; see Toposolid: Excavation Volume Parameters.
For the drawing set, build a schedule: View › Create › Schedules › Schedule/Quantities, pick the Toposolid category and add the Cut, Fill and Net Cut/Fill fields. Set the schedule's Phase Filter to Show New so the existing solid stays out. Building schedules is covered in schedules in Revit.
Revit site plan: the view settings and what must appear
A site plan is an ordinary plan view that differs in four settings.
| Setting | What to use |
|---|---|
| Scale | 1:200 or 1:500 for a single house, 1:1000 for a large project |
| View range | Put the cut plane above the roof so the building reads as a mass seen from above |
| Detail level | Coarse. At 1:500 every small detail becomes a smudge |
| Visibility | Turn off grids, section marks and room tags |
Switching whole categories off is covered in how to hide elements in Revit. Coarse detail has a second reason: RPC trees are heavy, and fifty of them on a site plan will slow the file noticeably.
A submission site plan here usually has to show seven things.
- The plot boundary, each side dimensioned, and the total area.
- The building outline and the setbacks.
- Natural and formation levels at key points.
- The ground floor level relative to the pavement.
- The access, yard and parking.
- Planting.
- The north point, scale and land use table.
That land use table is best built as a schedule, drawing figures from the property line and from the floor areas already set up. Do not type them by hand, because the moment the scheme changes they are wrong and nobody notices.
The last part is where Revit cannot help. Boundary marker coordinates must come from the official cadastral record, not measured off the model.
Try it: build terrain and set up a site plan
A forty minute exercise. It gathers the whole sequence for a toposolid in Revit, from sketching the boundary to the finished site plan. Work on a model that already has a building.
- Open the Site view. On Massing & Site, click the arrow under Toposolid and choose Create from Sketch.
- Pick Grassland - 1200mm, draw a rectangle about 20 by 30 m around the building, and click the tick.
- If Revit warns that toposolid and floor overlap, write the wording down.
- Select the terrain and record the three figures Area, Volume and Thickness.
- Click Edit Type then Duplicate, name it
NATURAL-GROUND, open Contour Display and set the primary Interval to 200 and the secondary to 100. - Click Add Point, choose Absolute, type 500 in the Elevation box and click a high corner. Repeat with 0 at a low corner.
- Count the contour lines that appear and judge whether the interval suits the site.
- Click Sub-divide, sketch a yard in front of the building, and change that region to Path - 350mm Concrete.
- Run Property Line, choose Create by sketching, trace the plot edge and read off the plot area.
- Set the Site view to 1:200 and Detail Level to Coarse, then open a 3D view and check the building sits correctly on the ground.
Frequently asked questions
I cannot find the Toposurface tool. Is my install incomplete?
No. Release 2027 removed it along with Site Settings, Split Surface, Building Pad and Subregion. Use Toposolid instead.
My terrain has no contour lines at all. Why?
The interval set in the type is far larger than the height range of the site. Open Type Properties, go to Contour Display and lower the Interval, typically to 200 or 100 on a house plot.
What does the toposolid and floor overlap warning mean?
Terrain is sitting on top of the building floor. Use Excavate to cut it, or lower the terrain below the floor level. The warning does not block modelling, but volumes are being counted twice where they overlap.
The file slowed right down after I added trees. What can I do?
Set the site plan view to Coarse detail so trees draw as simple circles, and avoid the Realistic display style while working.
Related articles
- How to create floors in Revit — terrain is a solid now, so it builds exactly like a floor
- Schedules in Revit — where the Cut and Fill schedule for terrain is built
- Room area in Revit — the source of figures for the land use table
- How to hide elements in Revit — turning grids and room tags off for the site plan