By John Flanagan
In Revit we use level constraints to control the height of vertical building elements such as walls and columns. When you are placing walls / columns, you can specify a base constraint and a base offset, a top constraint and a top offset.
In the illustration below we have four cases. The base level is 00 Ground Floor and the top level is
01 First Floor. The offsets can be either above (positive) or below (negative) the level constraints.
The first illustration shows the positive base offset of 800mm for the wall on the right. When you select a wall, you can set the height constraints in the property’s palette. Once a wall is placed you can select it and change its top and base constraints in the property’s palette. If you change the height of a level, the walls will move with it and any offsets will be maintained.