Planning to build, is it realistic? Young + Equity

It may be true that with my age I might not have as much life experience as some others with 30 or 40. But I think that has nothing to do with youthful naivety. They are rather different things in my opinion.

And which ones?

It doesn’t matter at all why and how, just let it be, instead of creating a side issue!

The fact is that you have no clue and that’s why you’re asking your question here in the forum.
You get answers... many go off-topic and don’t suit you... so what?

Thanks for the tip, but I currently and in the future don’t need to assume that will happen.

It’s up to you to take something from the answers or not. Nobody will hold your hand – and none of us, including you by the way, can look into a crystal ball here!

Just because you haven’t (yet) dealt with these scenarios doesn’t mean that a) they don’t exist and b) are not worth considering.

Your interjection was not worth considering but rather more like "Teacher, I know something.. I.. I.."
I’ll also tell you why I think that... Someone who bequeaths such a sum to their child at such a young age doesn’t just have pocket change in their account... By the way, they do this exactly to avoid the scenario you "considered"... They also know how to handle money, or rather have a (good) tax advisor...
Old-age poverty... I’m laughing my head off...

And always this knockout argument "you also have to live with uncomfortable answers"... Uncomfortable answers are a (good) thing.. simplistic, useless, or presumptuous answers are a completely different matter...

But I won’t get upset anymore now. It’s pointless...

Right, the OP is planning without his girlfriend, so all the emotional nonsense can actually be ignored. However, the information about how much money your girlfriend earns was also absolutely unnecessary, since her money shouldn't play a role.

The answers given to the OP are not just pulled out of thin air; they are simply things that life writes. Some may have experienced the scenarios themselves or have witnessed them to some extent within their family/friend circle. All these concerns/experiences are gladly shared with a young person. What he ultimately makes of it is entirely his own business. I am done.

Since I have received the answers to my questions, I don't think this discussion needs to go any further in all directions. I also don't want it to become personal or anything like that.

I thank everyone for the answers and also for the tips.

Sorry , that I still have to write something here, but this issue is really burning under my nails...

The OP clearly wrote that he does not want relationship advice here... totally understandable and repeated as well. Why can't some people here respect that?

1. He wants a house now
2. but his girlfriend does not want to get married yet

What an entry 50:50 in the land register means considering the gift tax issue, you experienced homebuilders don't need me to explain now (could be arranged via a private contract/interest-free loan, but the OP prefers to finance the house alone - period)

The hint that he should rather wait until marriage is nice - but see points 1 and 2.

and 3. maybe the girlfriend also does not want half a house on her back yet?

And again - the super great hint about the "imminent" parental support - related to the situation, taking into account the legally anchored retention and exemption amounts would have been acceptable - but just throwing the horror scenario "all the money is gone" - well...

So and now to finish "what I would do":
1. With 350k in the back, I would look for a monthly rate I can/want to pay
2. then I would check how much credit I can get for that
-> playing here with different equity contributions and watching how the interest rates move
3. that leads to different budgets based on the different equity contributions
4. find out what you can build with that and decide...

So, I would probably end up with a more modest number than you plan, since I would want to keep a nice part of the equity for the following reasons:
- with the excellent interest rate, I would invest the retained equity so that hardly/no loss or even a profit occurs
- separation -> pay installment + full additional costs alone
- possibly self-employment
- wedding, travel, pilot/sailing license, whatever...

So, I'm out here now...