To be honest, I don’t understand the problem behind your question. If you allow yourselves a "Yes!" to the question "would you like a bit more?" not only at the sausage counter (for 270g instead of half a pound), but also in the real estate market (for 600 instead of 400 sqm building land) and can afford to build at least under the assumption of 3k per sqm with 190 sqm living space plus a granny flat, then apparently you only know money problems from TV. In that case, it wouldn’t bother you in the slightest if and to what extent building gets more expensive. Being able to afford 600 sqm building land already speaks for solid finances and/or that the Stuttgart metropolitan area is very broadly defined and we are not talking about Rutesheim or Ditzingen, but at best about the "Greater Leinfelden area" (?)
Just imagine the time back: five years (= before Corona), ten years or more (before Lothar, before Kyrill, ...). From then until today, construction loan interest rates have dropped again and again, but building and other prices have also risen. These are not events that come as rarely as Halley’s comet. Suppose Putin / Hamas or the like were history next year and Habeck’s "heating ban" as well, chip shortages or delivery problems with heat pumps would no longer exist (there are still people who believe that a good fairy is born every morning). There are reasons why I named my info blog "Building Now," because luck with the hesitant is nowhere in sight. Betting on falling prices is something for fools who like to become poorer (in terms of purchasing power). Time does not heal prices. Even Kostolany would never have gotten rich by waiting if the thread of crises had once broken.
There is no "or" before an architect here. Construction companies and prefab house suppliers like to advertise that one does not have to pay extra for architectural services, but they expressly refer to "necessary" architectural services, i.e. those required to obtain a building permit. And of course, they allow customers to move windows around on the façade until everything looks balanced for symmetry monks or draw several appearance simulations. Still, I recommend never going to a general contractor instead of an architectural planning and tendering (no matter if stone or "wood").
As a currently also professional construction consultant and someone with overall four decades of experience in owner-occupied home planning, I can assure you that every saved architectural fee can be accounted 1:1 to the cost item "surprises," and that especially the large fee share of phase 5 pays off fully. In phases 6 and 7, it is even the case that without proper bidding, building will be more expensive (the only exception: with employee discounts at the building material dealer, this can be compensated to the extent that you effectively break even).
If you now go "unprotected" through an architect to a construction company (as said, independent of the construction method), they will be able to name prices to you. But these will have to be taken with caution, just like those estimated by a professional at the current stage of planning. They will give you prices for the (including the granny flat) 220 sqm that will make you think that the warners were all pessimistic doom-mongers and that building is actually cheaper than expected. But even without future increases, in the end it would only fit if you refinance and cut back painfully.
That’s very good – just as it is good that you want to select stone construction companies from the region. They are usually more recommendable and do not play you against the wall with their legal departments in case of complaints like the big names with the great brochures.
Who have you chosen for this drawing? – freelance architects (mostly in the cand.arch. stage) are a suitable address here, draftsmen less so. It is already very good not to have put together an amateur plan yourself. But you better still go to the architect afterwards only with the list of requirements and wishes despite having a drawing.
This is a very important point. So all finish-your-house providers (Allkauf house, Massa house etc.) are out right away, and actually also the turnkey discounters like Scanhaus Marlow & Co.
Resist the delusion that a general contractor is "the solution"!
I recommend the following procedure:
1. Read the existing threads on the procedure for house planning here using the forum search terms such as "house construction schedule," "Gerddieter," "individual contracting"/"self contracting";
2. Now visit construction companies and model home exhibitions. Choose providers with higher standards to be safe (you will need the buffer) and consider stalking by salespeople, i.e. get yourself a disposable email address and a prepaid dumbphone;
3. Go to financial advisors and also obtain a building ground survey;
4. Commission a freelance architect with phases 1 and 2 ("Module A" see "A house construction schedule, also for you: the phase model of HOAI!" - external, so googlable with quotation marks);
5. During the resting phase of the dough, visit construction companies and house manufacturers again – now with the architect’s preliminary draft – (but this time in the actually appropriate market segment), while you or the architect submit the building pre-application;
6. Derive from the feedback to your price inquiry a decision whether phase 3 (design) should be planned in stone or wood and commission the architect for the further path (see contributions on the above search terms).
Thank you very much for your input. Especially the recommended procedure is very helpful for us. I will read the posts carefully.
Yes, I agree with you, it may seem to some as if money does not matter to us, but we also earn our money ourselves and it is not unlimited. Especially with an investment of more than a million, I find it quite important to think carefully. Regarding the property, we are building in the district of Böblingen.
Why did you not mention, for example, Schwörerhaus among the prefab house manufacturers? I always thought Schwörer was one of the high-quality prefab house providers.
The more we think about it, the more we tend toward an architect-designed house. But of course that can still change. Everything depends on the plot of land we are assigned.