Why was my post deleted because it contains a link? Why can you even post links if they are forbidden? Such functions can also be blocked...
On the topic:
My parents' generation built with 8-9%, but at different (relative) prices.
So if interest rates continue to rise, prices cannot remain at this level in the long term. The demand for construction timber, insulation, etc. will collapse massively if you have to pay 4% interest on these prices.
My parents' generation lives in >200sqm houses with lots of trimmings that were expensive back then and unaffordable today; back then, they saved at most on insulation.
Today, I see posts here where people with 140sqm and 2 children still cut the basement and the garage from the budget.
Either everything settles again to "normal" conditions in the long term or the single-family house will simply become extinct.