Below-grade walls can be brought into cove.tool through the covetool below grade wall view in the respective 3D plugins. Make sure before you import below grade geometry you have determined whether it meets the conditioned space requirement as shown in the Below Grade Geometry Guide. Once geometry is in the 3D environment, it will appear below grade. Any geometry within the elevation with the below grade objects will also fall below ground, so be sure to remove any items in the 3D view that fall below these conditions. If you have building geometry that needs to be above ground and is visible below grade on cove.tool, proceed to the section below for possible solutions.
Below grade wall view:
The covetool 3D plugins include below-grade walls as an export category for geometry below ground. Wall Families modeled as Foundation or Retaining wall objects will be filtered into this view in the Revit plugin. Open the cove.tool below-grade walls view to check for any above-ground walls that may have filtered into this view, hide them, and re-export the views.
Check your Project origin point:
Based on the origin point selected between Revit's 3 origin points (Internal Origin, Project Base Point or Survey Point) make sure this point is at an elevation close to the ground plane of your model.