Most buildings contain multiple uses - perhaps a residential tower sits atop a parking podium. Or, a commercial tower includes a retail ground floor.
The Stack order property controls how discrete geometries stack on top of each other. The higher the number, the higher it stacks in the building.
Only geometries on the same layer can stack!
Stacking Basics
Stack order is not the same as Levels. While levels determines the number of stories or floors in a building section, Stack order is relative to other geometries in the stack.
A geometry with 1 level can be stack order = 1.
A geometry on top of that may have 4 levels, but it is stack order = 2.
Adjust Stack
To adjust the stack order, edit its value in the properties palette.
To add a geometry to the stack, Draw or move a geometry on top of another.
To adjust stacking behavior, select a force stack option.
Default - inherit Usage type stacking defaults
Always - stack if on the same layer
Never - never stack
By default, Building usage type geometries will stack if:
they are on the same Drawing Layer
AND
force stackis set to "default" or "always"
Stack Order is for building type usages! Roads, Paved areas, Basement, Generic Usages, etc do not stack.
Landscape usage type geometries will also stack on Building usages if the force stack property is set to "always." Use the force stack property to make landscape elements sit on top of building elements, to create rooftop gardens and green roofs.
Base Height
A Geometry can also inherit a base height, which controls how high the bottom of the geometry is from the ground plane. Changing the base height value lifts the geometry straight up off the ground plane by the designated amount.
Use Base Height to:
Simulate stacking between elements that are not affected by stack (such as generic geometries)
Simulate stacking on elements that are on different layers
For sky bridges / pedestrian crossovers between buildings
When the base height of the lowest geometry in the stack order is changed, everything on top of that geometry will remain stacked.
When the base height of a geometry above the lowest item in the stack order is adjusted, the lower stack items are not affected.
Drag a geometry up or down to change its base height
Lift a podium, sky bridge, rooftop element, tree, or any other geometry into place by dragging it straight up in 3D, without typing a number into the properties palette.
Switch to a 3D view. This shortcut does not work in the 2D top-down view.
Select one or more geometries.
Hold
Cmd/Ctrland hover over the selection. A move handle appears on the geometry.Keep holding
Cmd/Ctrland drag up to raise the base height, or drag down to lower it. A label next to the cursor shows how far the geometry has moved.Release the mouse to set the new base height.
Every selected geometry moves up or down by the same amount. Base height stops at the ground plane and does not go below 0.
Dragging changes the same base height value as the properties palette. When you drag the lowest geometry in a stack, the geometries stacked above it move with it.
In push/pull mode, hold Cmd/Ctrl and drag the top face of a geometry up or down to change its base height the same way.