And if you want to know the inside of the wall, for, say, insulation?

While I do not share bdfd's concerns about the plugin using measurements from the centre of the wall, that is easy enough to adjust for.

Nevertheless, put the plugin trough a little test. And while it behaved well on one or two sloping walls with a few cut-outs, it seems to have problems with many walls/openings - at least, I could not get the results I expected (but that may be me). So, I might still use the plugin, but I would double check the result.

ok