Construction costs are currently skyrocketing

For the next house, let me ask: How do you properly plan a metal roof? How do you prevent it from getting too hot? Probably too loud, so stick anti-vibration mats underneath. How do you prevent the mounting anchors of the photovoltaic system from making the roof leaky?

You have insulation in the roof or in a cold roof to the living space. That sufficiently prevents the heating of the living area and also the noise. We had such sheets on the old house. It was a gable roof, but with only a slight pitch. There was insulation on the ceiling of the upper floor, I think about as much as we have now in the bungalow. It never got too hot nor could you hear the rain. The latter only happened if the window was open during rain, then it was louder. We took down the sheets last year during demolition. After almost 20 years, they still looked like new. Although the service life was specified as 30 years, they certainly would have lasted much longer or will do so on the shed roof at my son’s place as well.

I would say that none of the newer houses with 2 floors still have brick roofs here, it looks much more modern, is quicker to assemble, and doesn't break. Here it is called Colourbond Roofing. Usually, the roof frame is also made of steel. You walk on it just like normal.

Back on topic again, today from around the world

However, the impression that buyers have to pay relatively more compared to their income is misleading. Despite the increase in costs since 2012, they are still significantly distant from the conditions of the seventies to nineties. Because in relation to their disposable income, Germans had to work much longer for their own property in the past than they do today....
This means that German property owners spend on average 25 percent of their income on interest and repayment. In 2012, it was only 23 percent. "But in the nineties, this rate was 38 percent. At that time, people paid a much larger share of their income to finance their property," said Hagen.

...Affordability index for real estate in Germany... Interpretation: The higher the index value, the more property Germans can afford with their income.

While the index was still below 40 in 1975, it is now just over 100. It peaked in 2010 at 130 index points. Over a period of 46 years, real estate relative to income was cheapest in 2010—and is still more affordable today than in any year between 1975 and 2005.

That can certainly be true, but unfortunately the additional costs have become significantly higher today! One must not forget that.
Besides, the whole life of people has changed. Consumption upon consumption! Vacation MUST be, 2 cars, 2 e-bikes, 4 cell phones in the household and I could go on with the list forever... Just all the streaming services for TV (know people who spend over 80€! per month on it...)
Such things didn’t exist in the 70s. I don’t want to say that everyone has everything, but the majority does. Life today can no longer be compared to life back then at all...

This means that German property owners on average spend 25 percent of their income on interest and repayment. In 2012 it was only 23 percent. "But in the nineties this ratio was 38 percent. Back then, people paid a much larger share of their income to finance their property," said Hagen.

Now it would be interesting to know how long financing with 38% of income lasted on average in the 70s to 90s and how long it now lasts with an average of 25%! Interest rates were also significantly higher back then, so theoretically the repayment should have been lower. It would also certainly be interesting to compare equity ratios from then and now. No idea if there were as many 110% financings back then as there are today? I strongly doubt that. And on average people definitely built more themselves back then and less turnkey, which of course also affects the loan amount.
To make it meaningful, factors such as household annual net income in relation to the loan amount should be included and compared.

So just comparing the pure shares of income seems a bit too narrow to me.

Nevertheless, you have to say that people were also satisfied with less back then and therefore accepted more restrictions.
Today many people always have to have the newest of the new (smartphone, TV,...) if necessary on credit.

It would now be interesting to know how long the financings with 38% of income in the 70s to 90s lasted on average and how long they now last with an average of 25%! The interest rates were also significantly higher back then, so theoretically the repayment should have been lower.

In the high interest phases, 1% repayment was sufficient for a term of 32 years.