How do we build most economically?

Apparently, you are not yet really familiar with what awaits you soon.

So what I would do:
Determine: What can I afford... How much can I spend.
Construction cost estimation: For this, the general contractor (GU) must provide the question and answer. An initial preliminary planning, pricing of your special requests, and clarification of what is not included in the services of the GU.
At the same time, clarification with the tax office.

After that, go to a bank with the current costs and clarify the financing feasibility in advance.
Meanwhile, if desired, one can sign a work contract but reserve a financing contingency. If the bank does not offer good conditions or even rejects, the contract must still be cancellable without the usual 15-20% contractual penalties.

@Der Da: Well, I would say it just sounds like that. We already own property, but it was bought finished and is currently being sold. I also know exactly what we can afford financially. I am a construction financing advisor myself. It's just that we have never built ourselves, and friends, acquaintances, and relatives have only ever built independently and never with a developer or general contractor. That's why all my questions. Unfortunately, there are too many sharks in this field, and we don't want to be taken advantage of. ;)

@Michael: Great, that was very informative. But then we've already reached point 3. :)

If you yourself work as a financing advisor, then you must have already had countless contracts and construction service descriptions right in front of you. Have you never looked into them? Or do you only finance finished properties?

I am not a clerk. I worked at a very large bank and did not have to read the [Werkverträge] in detail, nor the [Kaufverträge]. However, I actually financed new buildings rather rarely. Checking contracts is more a legal department task!!!

@Kisska88 The approach of economical construction & quality should be for every builder: • the health and comfort of the users • the most extensive creation of accessibility possible • an appropriate design of new buildings, where the user can identify with their building and thus promote careful handling • the contribution to global climate protection • taking into account the already foreseeable climate change today (long-lasting heat waves in summer, increase in heavy rain events, stronger storms) • the durability and recyclability of the constructions and components "In short, the goal of every builder should not be cheap, but economical construction. The goal is also, with defined predetermined qualities and the life cycle of a building, usually about 50 years, to minimize the annual total costs. Because economical construction means not only focusing on the immediate investment but also including the total costs of a building. As total costs, the sum of capital costs, operating costs and environmental follow-up costs should be considered holistically. Confucius said “Man has three ways to act wisely” First by thinking: That is the noblest. Second by imitation: That is the easiest. Third by experience: That is the bitterest.

I hope you don't want to imply that I mean "cheap" when I say "economical"... Imagine: We are planning a house that is as independent as possible for the future, which can still be used later without children. And still, I don't want to be screwed over by anyone during the construction... :p We are both not stupid and know some new buildings and know how it can go or not. In the end, we also know what we want. It's just that the way there is not an easy one... That's why I signed up here. ;)