Global Parameters in Revit can be used to assign a parameter value across an entire project. It has many uses when it comes to building design. One example would be to utilize Global Parameters to drive mounting heights of the highest operable parts of restroom accessories. The image below shows restroom accessories which have been randomly placed in a host wall.
In the Manage Tab > Settings Panel, select the Global Parameters tool, and assign the value for the mounting height as needed per the projects specific Code Requirements. See Images 4 and 5.
To assign the Global Parameter to other applicable restroom accessory heights, select the corresponding dimensions for those accessories. Then select the newly created Global Parameter from the Label dropdown in the Ribbon, as shown in Image 6.