Which building regulations make new constructions so expensive?

One can always construct extreme cases. 70-year-olds certainly will not make up the largest proportion in new constructions; around me, it's actually exclusively families in their early to late 30s building.

And with us, it's exactly the opposite. Of the 20 places so far, three families, including us. Half of the places are still undeveloped, but currently there are definitely more retirees than families. And when I look around in this forum, building at an older age is definitely not a constructed extreme case.