> So is the growth of housing stock lower than the population growth?

National averages can hide a lot of local issues. I'm in Berlin right now, I'm told by locals that it's lost the reputation it used to have for "cheap" housing. (It's not cheap, but I'll have to take their word for it that it ever was, I've not found historical purchase prices vs. income graphs like I've seen in the UK).

Meanwhile, if you're willing to look at 115 year old places in the arse end of nowhere: https://www.immobilienscout24.de/expose/165084645?referrer=H... or https://www.immobilienscout24.de/expose/164269182?referrer=H...

New places are more expensive for various reasons. The land in Berlin can easily be as expensive as the cost of building a home on that land, because fixed supply and a lot of demand. Even if the land was free, the cheapest new build cost I've seen is more than twice the price of the more expensive of those two, but will almost certainly also make up for the full price difference (including land at Berlin prices) just in reduced energy bills before the mortgage is paid off.