Which developers build with POROTON in SH

By the way, Wienerberger has a plant in Kirchkimmen. Maybe just ask there who gets supplied nearby?

Seems like there's something like a aerated concrete equator. [...]
I would also like to know why that is..

An "equator" would be a line between two areas, but there is probably a third one in between here: the alluvial gravel belt (roughly from southern North Rhine-Westphalia to Hesse), I live right in pumice land. Aerated concrete (gas concrete) "originates" from Sweden.

Kirchkimmen is, however, far away from SH.

Kirchkimmen is far away from SH.

OL or OD - as long as it's Italy ;-)

Sillyhead 170 km is not far at all. I drove (20km) further for my insulation from Pagoni.

As I already wrote above, bricks are not ideal for long distances mainly because of their mass - so basically the exact opposite of insulation. ;)