On Land

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At Rill Architects we run ArchiCAD on Mac OS X. If you work at Rill, this is your stuff. If you don't, but you work in ArchiCAD, you may find something interesting. Anybody else, I don't know.
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Here is a massing model showing existing conditions and a proposed addition. It is mostly done with renovation filters, with a couple of tweaks from graphic overrides.

existing-new massing model

Existing is overridden with one surface, the light color in the picture. If you are OK with existing elements not having fills in elevation, you can leave this override on. If you want the fills in elevation, you need to turn the surface override off, and switch it back and forth manually. This setting can't be saved with views or filters. We really need per-filter renovation overrides.

New is overridden with a different surface, the red in the picture. New elements are generally shown, not overridden. So the surface override can be left on. It is currently the only active override setting for New.

There is a new renovation filter, 07 Massing by Status. Existing=override, Demo=hide, New=override. Again, in all other filters, New is shown.

These are the graphic override rules:

Site Green finds 3D elements (in practice, they are meshes with the occasional slab) on the layer C Site3, and changes their uncut surfaces to 'Grass - Green'. Graphic overrides happen after renovation overrides, so while the site has existing status, it is not shown with the white color.

3D Lines Match finds All Types of elements, and changes their Line Pen to a medium gray pen. (It's our pen 137 in the picture, the default pen 2 would be fine too.)

Glass can't be overridden within windows and doors. (This would require attribute-level graphic overrides.) If you want clear openings of any sort, you have two options I can think of:

One way is to use 'Filter and Cut Elements in 3D' to hide the doors and windows. This will give completely empty openings.

The other is to use a graphic override rule similar to the site/grass rule, where doors and windows are chosen to be overridden by a clear surface. But, all parts of the doors and windows will be clear, not just the glass.