Phew, some people here might know something about house construction, but when it comes to finances, it obviously gets tricky here and there when I read "the gambling." Furthermore, there are comments that really don’t belong ("You can be as stingy as you want!" - "Then have fun gambling!" - "Less net income than a Daimler assembly line worker!")
Also, presumptuous advice like "get used to rounding up so you don’t forget anything" is, of course, completely out of place. The exact figures give me as an observer a good feeling: Here someone doesn’t calculate - like many others - roughly, but has an exact overview of their financial situation. That is commendable. Such people are rather unlikely to forget something and especially unlikely to not round up the total sum in their head. By the way, you can of course include invested money as equity without liquidating your portfolio - just with a significantly reduced loan value.
Let’s summarize the situation:
Total volume: 800k
Equity:
210k available
130k from the parents
25k comes from the car
===============
365k equity
Monthly ancillary costs of the house: approx. 400€ (chimney sweep, home insurance, household insurance, trash, water/sewage, reserves 1€/sqm/month, etc.)
Our balance decreases to 2,762€ (+ no longer needed rent of 559€) = 3,321€
Wife on parental leave (65% of net average) + child benefit are 481€ less + additional costs of 200€/month for the child. When the wife goes back to work, it will be 50% or 30h/week --> so about 65% of the original salary will remain.
Our balance decreases to 2,081€ (+ no longer needed rent of 559€) = 2,640€
I would reduce all balances by 600 euros because I wouldn’t count on the portfolio’s return as fixed. That will work in the long term, but to regard it as fixed monthly income seems at least daring. When it drops by 30% once—and it will—it doesn’t feel good. And then you definitely need "balls" to sit it out - that won’t get easier if the house is pressuring you from behind ;) Better see this money as a buffer.
Then the balance, after no longer needed rent, goes down to about 2,000 euros.
With a 600k loan and 1% interest + 2.5% repayment, we are at a rate of 1,750 euros.
So in this situation, I would want to adjust the equity: If you include the parents’ 130k and the full portfolio (including the car and 60% loan-to-value on the portfolio I would assume) you end up with 280k equity - ergo 520k loan and a rate of 1,500 euros. The advantage is that the money in the portfolio can continue to grow.
Alternatively: liquidate the portfolio, take 180k from it + 25k car + 130k parents = 335k equity, resulting in a 465k loan = rate of 1,350 euros.
Risks seem manageable to me up to this point, especially since solvent parents are in the background if necessary.
Personally, however, I don’t know if someone whose hobby is "growing money" should do it this way :) You are in a comfortable situation, and all the money you put into your own house could be better grown elsewhere. So if buying a house is an investment for you, I would reconsider it - if it is a lifestyle decision, then "Go for it!"