Realistic financial planning for KFW40 prefabricated house?

I sometimes wonder how some people operate here. From first contact to moving in, only 19 months have passed for us.

You lack the imagination for other life situations: no land, no equity, no income due to parental leave... there are countless reasons why it can sometimes take several years. You can bridge the time with planning.

I am 1.80m tall and regularly bumped my head on the sloping roof in my youth

Nevertheless – take a look at the mentioned post, which I am unfortunately not allowed to link to you here – with the knee wall, the window opening is also pushed upwards. A clear finished dimension of around 120 +/- 20 cm remains, no matter how you twist and turn it, the green area corresponds to a knee wall height.

Do you think we’ll come out cheaper with a timber frame house that is not a prefabricated house? We know an architect and a landscape engineer (who is also familiar with VoBB) in our circle of acquaintances. Maybe we should also assign trades ourselves instead of planning a turnkey project? I just don’t know if we would save anything in the end, since that will certainly lead to more problems (tradespeople don’t show up, don’t finish on time, follow-up projects get postponed, etc.).

In timber "frame" construction (actually it's timber frame panels), you will practically only find providers for factory-prefabricated houses. With some "exotic" providers, the depth of on-site construction might extend a bit further, but these are basically also prefabricated houses, usually even at owner-operated small providers. These are more suitable for customers with niche demands, but for standard (including standard KfW40) projects, they are not the right address for bargain hunters. Tendering and awarding contracts – you yourself mentioned examples of critical points – is rough seas; I would advise avoiding them even with a proper captain in your circle of acquaintances, especially if you only have a pedal boat. Besides, you also have to leave a margin for trades to a general contractor – whether stone or wood – that’s part of building a fair house. If you have little money, you have to save on your special wishes – that actually works best.

But that has nothing to do with what you mentioned.
If you have to "fight" for a plot of land, the model house park is not to blame and a regional construction company won’t build anything on it either.

That was never my point, brother.
On the contrary: After many visits to the model house parks, we were sure it would be prefab house manufacturer A, B, C, or D. Among other things, the tip here in the forum/private and the fact that we are building with a basement brought the regional solid construction builder into the race. For this, I am very grateful to the forum.

Hello everyone,

thanks again for your feedback!

Here is a status update: We are still in the phase of collecting quotes.
Here is a brief interim report with lessons learned:

+ Save on earthworks: We have demolition of the existing building with a basement. That means the "Wunderbox" earth disposal is not necessary for us, as we can use the excavation of the old basement.
+ Compare offers from prefab house manufacturers: It is often suggested as a tip to go to prefab house manufacturers with a finished architect’s plan to compare offers. So far, I can only recommend this to a limited extent. I would definitely create a plan so that, for example, you get a realistic cost calculation regarding the windows (cost drivers!). But some prefab house manufacturers also have relatively good promotional houses that can be used as a starting basis. As I said: don’t forget to have cost drivers (windows, floors, stairs) calculated directly.
+ Reduce basement costs: We are currently dealing with the topic of basements. Not so easy... For cost reasons, we want a usable basement that can be a bit cooler. An office will go in there but 18°C-20°C is fine. Now the house-building companies are calculating directly with insulation of all walls and the floor slab. The insulation then allegedly has to meet the same standard as the house, meaning we now have to consider whether a KFW house + KFW40 basement is really feasible, or if we have to downgrade to KFW55. And if you have to insulate the basement anyway, maybe a living basement is an option right away?
What makes me suspicious here: A prefab house provider told us that you can also simply insulate the basement ceiling, that is the transition from basement to house. Meaning Kfw 40 house + uninsulated basement. That seems to me the much more logical approach. Am I missing something here? Or do the other house manufacturers deliberately offer the more expensive variant because they hope for a higher commission?

I will report as soon as we make progress.

Uninsulated basement would be to my knowledge without heating. You want an office, right? utility basement also allows a different ceiling height than a residential basement with an office. But others surely know more about that than I do.

Uninsulated basement would be, as far as I know, without heating. You want an office, right? Utility basement also allows a different ceiling height than a living basement with an office. But others certainly know more about that than I do.

Yes and no. There will be no underfloor heating, but maybe we’ll install an electronic emergency heater for the one week a year when it gets too cold. Basically, I always prefer it too warm rather than too cold, I never have the heating on at the moment and my PC also radiates good heat. If I get cold feet, I can just put on slippers if necessary... We’re planning the ceiling height to be about 2.50m in the utility basement.