This guide explains how to use the 3D topography tools in Revit and the associated building pad tools.
The guide assumes knowledge of setting up site coordinates and linking.
- To create the topography for a site, reference in a survey or OS map that gives the extents of the boundary.
- From the Massing & Site ribbon, Model Site panel, click the Toposurface
- Toposurfaces can then be created using 2 different approaches:
- Place Point
- Create From Import
- Allows you to place points around the site to identify the boundaries. Each point clicked has an associated Elevation value that can be entered before clicking to place the point.
Points can also be edited after placement in the instance properties by selecting that point.
Note: Multiple points can be selected at a time to elevate those points in one go to the same level.
- Edit values to match that of the topographical survey
Note: The Revit template is in mm, surveys typically display units in metres
- Points placed on the edge will form the boundary of the toposurface, points placed on the inside of the boundary will simply adjust the height.
CREATE FROM IMPORT
The Create from Import tool has two options
- Select Import Instance allows the selection of a 3D DWG containing contours and automatically creates the toposurface from the geometry in the import file.
- Specify Points File uses points listed in a CSV to bring them in.
The CSV file must be formatted X,Y,Z. Any additional information from the points file is ignored.
When importing a points file, a prompt will ask for the units the points file uses. Specify the units and click OK.
- Once completed placing the points, click the Modify ribbon > Surface panel’s Finish Surface
- Finally select the toposurface and, using the instance properties, change the Material property to give the graphical representation required.
Once a toposurface is created, it will follow the extents of the widest points and not trim to meet each point.
- To trim the surface to match the edge of the site boundary, from the Massing & Site ribbon > Modify Site panel, click Split Surface.
- Select the surface to split
- Trace around the portion to be removed.
- Once completed, click the Modify ribbon > Surface panel > Finish Surface
- Select the split surface and press[Delete] on your keyboard to remove the segment.
CREATING BUILDING PADS
Once the topography has been created, a surface will exist that undulates to match the site. Building pads can then be used to cut a hole in the topography for the building to sit within.
- From the Massing & Site ribbon > Model Site panel, click the Building Pad
- Once drawn, from the Properties palette, change the Elevation offset from level value to specify the height of the building pad (this should be the lowest floor of the building)
The building pad will cut through the toposurface to give a flat level for the bottom of the building.
- The building pad tool creates a floor slab as the base that can be modified by selecting the pad and clicking Type Properties > edit Structure.
- Building elements can now be placed without being obscured by the toposurface.
Subregions are regions within the surface allowing different materials to be applied.
- To create a subregion, from the Massing & Site ribbon > Modify Site panel, click the Subregion button.
- Trace the subregion required.
- Once traced, click the Modify ribbon > Mode panel, Finish edit mode button to complete the sub-region.
- Once drawn, the subregion can be selected and from the properties palette, a different material applied from the rest of the toposurface.