Box For Device

[augie47]

Augie maybe you can clarify. Wouldn't that be 16 square inches for the actual opening cut into the drywall not the box within the wall? Wouldn't a 4" box with a 2 gang opening be the same as a 2 gang 4 11/16" box opening?

The requirement is enforced locally by the building inspector so my experience is anecdotal. They have required me to putty pad my 4-11/16.... you very well may be correct as I didn't challenge it.