House construction project - Reality check

Total term (forecast) 36 years, 3 months Based on the following key data Loan amount 461,000 € Interest rate (calculated) 3.96 % Monthly installment (calculated) 2,002 € Repayment 1.25 % The numbers speak for themselves.

The numbers speak for themselves.

But please calculate with a financing requirement of 500k for house construction costs of 500-510k. The rest, like kitchen, etc., does not factor into the mortgage.

At my age (33), is the approach and planned repayment within 30 years reasonable, or would it also be reasonable to stretch this until retirement with the currently known figures?

I definitely do not recommend, 1. building alone as a single person and 2. still seeing yourself in the same house in thirty years. In a family nest, Mrs. Right may be reluctant to be the newcomer (although moving into a bachelor pad is still less bad than into the love nest of the predecessor). And "building for old age" is currently, when you are only 33, already something 58-year-olds are doing (with a trend towards younger people). So in my view, you better replace the calculation "paid off by retirement" with "little remaining debt at the time of the mortgage refinance (= building the second house)," and you should wait with building the first house until you find the co-creator (I assume a heterosexual partnership here; regarding same-sex relationships, I cannot estimate the likelihood of aversion against the predecessor in the nest).

I would ask why someone would need a house at all as a single. I would buy a nice apartment and if a wife and child come along, then sell it and build a house.

Of course for the same reason a family wants a house: to live in it! That the numbers don't exactly support it is one thing, but one can also read the quoted post as implying that singles would not be entitled to live in a house. It is surely up to the thread starter to decide how he wants to live. With the same justification, one could ask every VW, Audi, BMW, Mercedes, etc. driver why the expensive car; after all, even a Dacia gets you from A to B...

In the Heidekreis, there are definitely good used properties that are around 350k. The first property does not have to be perfect everywhere and does not have to be only 3 years old. Houses from the 2000s are very, very suitable for living. The advantage of debt is that it is subject to inflation. As long as your salary more or less keeps up with inflation, the property will eventually be cheaper than comparable rent.

500k would be way too much for me. At your age and single, I would still want to do a lot and not be a financial slave to the house.

Is it reasonable at my age (33) to manage the approach and planned repayment in under 30 years, or would it also be reasonable to stretch this to retirement using the currently known figures? (~35 years repayment of the loan) So, taking the 2k€/month as fixed and excluding special repayments. Is this still a justifiable term for repaying a construction loan?

The problem is that building a house for a person with this salary and without significant equity or their own paid-off land is too expensive. At some point, the thread of wishful thinking just breaks. And honestly: I don't believe that you would even get a loan of this amount as an individual under these circumstances.

In the Heidekreis there are definitely good used properties available around 350k.

Exactly. But please don't drift towards the new-build properties with catalog prices starting from.