Overview

it is possible to modify stacked leaves (layers) of a compound wall. 

Method

For demonstration purposes we created this compound wall with blockwork (CMU) stacked on a Concrete plinth, the inner faces are coplanar:

With Graphic Group (GG) Lock off (in the Icon Locks toolbox or the Locks dialog, they are interlocked) it is possible to:

1. extend the top of the concrete plinth
2. raise the base of the blockwork (Note that 1. will not automatically do 2. They are separate elements once GG is Off)
3. butt join the concrete plinth
4. butt join the blockwork

Note that the window perforates both inner leaves.

Still with GG off individual portions of the walls can be multi-selected and have the same operation applied to them; in this example, raising the base:

We suggest that these methods be used sparingly - too many modifications to wall segments could prove unwieldy to manage.

It is worth thinking about the sequence of operations when using these methods.

Similar techniques can be used to deal with intersections between elements, typically structural columns and walls:

There are two methods. The first requires a number of manipulations:

• Turn Off GG lock, try to break each of the inner leaves individually and then manipulate each leaf individually.

The second method is much simpler:

• Leave GG On. Break the whole wall. Turn GG Off. Join the outer leaf.

Tip: Do this in Top View using intersection snap, not in the 3D view.