How to add elevation to a raster cell

[BenFord]

Hello,

I am doing a viewshed analysis for a city using a 30m DEM. I need to add building height to the DEM. Does anyone have any suggestions on how to do this?

I have drawn out polygons where the buildings are, and added a "height" column in the attribute table.

[DanPatterson]

One way...

Convert that building to a raster using the height field to assign a value to the building (NOTE set the surrounding area as zero)?

You can then add the building raster with the dem and your building will appear as an "extruded" feature in the terrain

[HeatherSmith]

You can visualize your building polgyons as 3D extruded features using the extrusion control on the appearance tab of the ribbon: https://pro.arcgis.com/en/pro-app/latest/help/mapping/layer-properties/extrude-features-to-3d-symbol... 

I'm not sure if you can use extruded polygons for viewshed analysis, but if not, you can convert the extruded polygons into multipatch features using this tool: https://pro.arcgis.com/en/pro-app/latest/tool-reference/3d-analyst/layer-3d-to-feature-class.htm