Perforated Surfaces

This is basic, but useful. While messing around in Maya, I kind of reverse engineered the manner that subdivisions can be attached to one another to create larger more complex topologies.  By using the principles for aggregation in reverse, this technique allows you to create geometrically resolved perforated surfaces.  The above image shows a simple case: Create a polygon surface, extrude all the faces in plane but with an offset, delete the new faces, and convert to a subdivision surface.  This can be done selectively or in more complex scenarios to produce topologically singular perforated surfaces.