To add a spot height to a mesh; have the mesh selected, AND the mesh tool selected in the ToolBox, set the Geometry Method to Polygonal, then simply double-click on the mesh, in the new dialog select your Mesh Point type. Now you can select the point and set its ‘Z’ height from the Pet
If you are designing a new stair you may want to check if it complies with the minimum height clearance rules that apply in your country. This is very easy and helpful with the Cadimage Stair tool, just go to the Settings > Head Clearance Plan For ARCHICAD 20 Settings>Symbol>Head Clearance and edit the
You can get the Dimension Tool to automatically dimension the height of openings by ticking Display the Height of Openings as well, within the Dimension Details section of the Dimension Settings.