How many offers and how far do they go?

We do not have a house bank at all; I must even admit that I have not been to a bank for 15 years, except to withdraw money when there is no ATM nearby. Therefore, we went to the broker and the insurance company. The insurance company's offer was not good, and the offer from a bank through the broker was surprisingly good – it is even the local Sparkasse. The decision was not difficult (we expected a higher interest rate). Perhaps, besides our income, the property we own and our equity also played a good role.

That local banks are always more expensive than online providers or intermediaries is indeed a myth. The cheapest providers are those who can refinance themselves best. Administrative and risk costs impact all banks somewhere between 50 and 60 basis points, regardless of the distribution channel.

They all want to earn money quickly ... So do we

We had originally obtained 5 offers.

Proposals or five ready-to-sign offers/loan agreements?

These were proposals based on our information and data including interest rates, repayment plan, etc. We had conversations with 4 of the five providers in advance, each lasting 1.5 - 2 hours. Only the 5th, who was recommended to us by our homebuilder, did not speak directly with us. His offer was therefore immediately discarded. With all the offers, we only needed to agree and the contracts would have been prepared. After the type of financing was finally decided, I only asked the remaining providers for the interest rates. When it became definitive, only the "GO" had to be given and the contracts were on the table with the agreed interest and repayment rates. One thing to add is: I had concrete ideas about the manner of our financing. I listened to everything, immediately said at certain points (e.g. building society savers) that it was not even worth trying, and adopted useful additions to my ideas.

Hello!
First, you need to be clear about what you want! Long security = long fixed interest period. Small annuity = low repayment rate, etc.

Given the interest rate level, I recommend a long fixed interest period, a higher repayment rate (at least 2%), and special repayment rights.

Who did you ask? The house bank? That should generally be more expensive. I would ask brokers and also an internet bank. Too many offers is not so great either.

So with the first two paragraphs, I can only agree with you.

But I see a request for construction financing with an internet bank critically for my part. Internet banks (as the name suggests) have no direct people on site, and if something does not fit or unexpected problems arise, it is difficult to get someone face-to-face there.
From experience, you are much better off with banks that are located locally (but it also depends a lot on the consultant in charge). The interest rates may be higher than those of internet banks, but I ask myself: Do I want to pay a little more money and in return have arising problems solved and quickly have someone at hand if something happens; or do I want the lowest interest rate and hope that everything goes well and that I do not have to refinance, suspend repayments, or similar again.
Moreover, the differences, depending on the local bank, compared to internet providers are sometimes really marginal.

In addition, local banks do not let customers suffer so much when major difficulties actually arise. On the one hand, this damages their reputation, which can be a death sentence for regional banks. On the other hand, a loss from a home loan weighs heavier for smaller banks than for large internet banks, which is why the customer is viewed quite differently here.