Property reserved. Financing is pending

Hello,

a few months ago I already opened a topic here, but the construction area back then has still not been developed. However, now we have reserved another plot :-).
Therefore, it is now the final sprint and decisions have to be made.
For this reason, I would like to ask for your opinion(s) and suggestions regarding my project:
Income (net):
Man: 3,100€/ month (incl. company car)
Woman: Minijob 120€/ month, but still looking for a 450€ job
Child benefit: 184€/ month
Equity: approx. 120,000€ (current house) + 20,000€ savings

Expenses:
Architect house: approx. 245,000€ (ALL IN, incl. (underfloor) heating, tiles, etc.)
Plot of land: approx. 95,000€ (incl. connections)
Additional costs: approx. 5,000€
Interior furnishing: approx. 30,000€

==> So we still have to finance approx. 235,000€.

I have now received the following offer from Interhyp:
Term: 25 years as a complete financing
- effective interest rate: 1.81%
- repayment: 3.18%
a. 230,000€
==> 954.50€/ month
b. 240,000€
==> 996.00€/ month

I think this offer is more than good, but I am missing some other comparison values. I had also contacted Dr. Kleist, but unfortunately have not received a reply yet...
I also want to give my house bank a chance, even though they certainly will not or cannot offer me such a deal...

Questions for you:
1. What do you think of my project?? Realistic?
2. Which brokers with a good reputation could and should I contact beforehand??
3. What experiences have you had with Interhyp??
4. Furthermore, the offer includes an option for special repayments of up to 5% annually.
If I use this, will my monthly burden decrease or will the term simply be shortened??

Thanks in advance to all who answer!!
[Grundriss Effzeh]

a) Houses do not sell within a month -> hard to count on the existing building - especially -> where do you even want to live once you have sold your current house? b) 5k€ ancillary costs are very low / too low even including connections c) 1.8% interest rate is doable - personally, I would rather fix it for 15 years, but that depends on preference.

a. Buyers of the current property are already present and waiting for us. b. The incidental costs are only the notary and other remaining paperwork. c. Thought 1.8% would be great for 25 years... With 15 years I still have the problem or the anxiety of the initial financing with whatever interest rate will be current then....

Which providers should I contact additionally?? Suggestions?

doesn't take everything so seriously at the moment. Yes, 1.8% is good. Wastewater and co, carport, kitchen, access path, carpets in bedrooms, paint is already all included?

Yes, including wastewater and co, as well as kitchen, sanitary, etc.... Is it possible to do even better than 1.8% over 25 years?? The nearly 1000€/month is still manageable for us after ALL expenses (detailed table), as long as my wife doesn't earn more!!

b. The additional costs are only the notary and the remaining paperwork.

And where are the other ancillary building costs, which will of course arise, hiding? Or are you buying house + land from a single source, i.e. from the developer? Rhenish greetings