House purchase with construction loan repayment rate

Very interesting how opinions differ here. From harakiri to well affordable even without a granny flat. Well, what am I supposed to think about that now.

It remains that nearly a third of the income goes toward repayment. According to the internet, that's okay; according to some here, definitely not. Hmm... I don't know.

And on the topic of parents: I know many people whose parents contributed some tens of thousands of DM in the 70s, which was normal, and I rather have the feeling that this is no longer so common today. But my feeling might be wrong.

It's probably even more normal today than before. I wrote this in another thread: now even more is inherited than before.
Here in the Düsseldorf area, the vast majority finance with a considerable chunk of equity capital from their parents/grandparents.

If there was so much money in my family that one had to worry about inheritance tax and negative interest rates, I would gladly accept the capital injection.

But if I couldn't manage the ongoing financing without their help, I would think twice. My pride would be too big for that.

The one-third rule of thumb is relative. Certain expenses are relatively fixed and do not rise with income.
Example 1: 10,000 household income. 3,000 euro installment.
Leave 7,000 for living and ongoing (additional) costs. More than enough. Electricity stays equally expensive. Insurance also within a certain range. Food costs do not increase proportionally with income.

Example 2: 1,000 euro household income. 300 euro installment.
Covering all expenses from 700 euro becomes significantly more difficult.