Am I creditworthy as an individual in the following situation?

You are talking about repayment of 750 + 300-350. that is more than 50%. That would be too much for me personally.

Besides, I see little room left after the house is finished to do the rest around it.

In addition, 750 with 25 years fixed interest probably comes to 2.5% interest; with that, you would still have more than 60K remaining debt.

And in the meantime, you still have to renovate the upper floor for the children and then probably take out another loan.

What does the offer say?

Where is the problem with 60,000 remaining debt?

Are you all financing here with a fixed interest rate until the end of the loan?

So with 25 years fixed interest and 60,000 remaining debt, I would have zero worries.

I also finance for 25 years but my remaining debt is significantly higher. [emoji4]

O.k, the loan is also significantly higher.

Where is the problem with 60,000 remaining debt?

It was just a hint; especially since the attic floor for the possible children is not yet developed and the 200K is already ambitious for a house with all the trimmings.

So, a follow-up loan is certainly out of the question.

Tell me, do you need cars there to get to work?
Have you ever kept track of your expenses?
Household budget? A car costs 500 plus fuel per month.

Statements like these bother me:

“an age-appropriate house is a must, so on one level...”
And “construction must take place within 2 years”
when one should be more modest.

I don’t know how high the house price is, apparently it fits (didn’t read the second post today)
How much additional construction costs have you planned? Is your calculation correct? With your rather low income for building (otherwise good and expandable) you have no buffer, as already said: where is the expansion supposed to come from? Why don’t you want to take out the loan together? It can’t be fear of separation, because your income alone can’t sustain you with the house in the long run.

I have the feeling that the house construction and costs are being taken too lightly. Also, miscalculations and consequently selling the house is not so easy out in the sticks...

881 € without residual debt after 25 years

60 K after 25 years would be okay, then there would still be 13 years until retirement.

The risk is rather the expansion measures you mentioned - but they would only occur if there is a second income anyway.

The important thing for me is the estimate of about 2.5% over 25 years.

In 1-2 weeks I will be wiser. I will then give feedback on whether my planning withstands harsh reality.

So, a follow-up loan is certainly not an option.

Tell me, do you need cars there to get to work?
Have you ever kept track of your expenses?
Household budget? A car costs 500 euros per month plus fuel.

Statements like:

“a must is an age-appropriate house, meaning single-story...”
And “it must be built within 2 years”
bother me when you should be aiming lower.

I don’t know how high the house price is, apparently it fits (I hadn’t read the second post today)
How much incidental building costs have you planned? Is your calculation correct? With your relatively low income for building (otherwise fine and expandable) you have no buffer, as I said: where should the expansion come from then? Why don’t you want to take out the loan together? It can’t be fear of separation, because your salary won’t support you with the house in the long run.

I have the feeling that the house construction and costs are being taken lightly. Also, miscalculating and consequently selling the house is not so easy out in the sticks...

A car is necessary, but a carpool exists. I have kept accounts for over 2 years, and I stay under 900 € fixed costs (including expenses for the current apartment and the entire car). The difference is used for saving, two building savings contracts, and "luxury."

Separation, parental leave, illness create several scenarios where one salary must suffice.

Detailed costs will be clarified within the next 1-2 weeks. My priority was the creditworthiness. I am quite aware that I could crash with my ideas. But I must have a realistic budget in mind when I go to the architect.