DEM- Change height under building

[RickeyFight]

I am trying to change a DEM to have the same elevation under a polygon. Is there a tool or process where this can be accomplished? Imagery and Remote Sensing​

My goal is to add this dem to arcgis pro. I want to add 3d buildings to the layer without the building being off the ground.

[DanPatterson_Retired]

If you polygon has an elevation, determine the difference between it and the surface.  I assume that this would show the elevation difference that you want to fill.  Then use a con statement to fill the area by that difference.