Floor plan design single-family house solid wood construction 140 sqm in Lower Saxony

The provider can also have a completely different wall structure – but then it has nothing to do with a log house anymore...

That explains a lot. The wooden house builders have to "religiously" commit to one approach (log/log beam, solid wood, or similar) – or they risk not adapting their systems with convincing results to current standards.

The blame rather lies with the development plan or the eaves height.

No, a development plan does not have the task of compensating for defects in the system design of individual house providers. Eaves height specifications are basically purposeful, and in your case also fundamentally not unreasonable, even if almost every builder would like more.

There are some good manufacturers who could build what we imagine – but we also don’t have 500k just for the house in the budget. Therefore, some unfortunately fall out right from the start. I also have a catalog from Stommel here, but I had them on the “too expensive” list. Am I wrong there?

As I said, I don’t personally know if they also offer shell houses; at least convinced me that they now build quite respectable houses fitting into Posemuckel/Ww. (I have since found it myself, here they build with Fullwood) mentioned in post #20 that this manufacturer also has detail weaknesses. But within the timber construction scene, it really should not be difficult to find another who can connect compatibly.

Precisely the "only between-rafter insulation" combined with "only 4.0m eave height" and then of all things giving away valuable 24-30cm of between-rafter insulation and thus additional headroom is just ridiculous - isn't it?

Maybe he doesn't like the unbearably tedious work of between-rafter insulation? But that's easy to do with a handball team in a weekend as own work ;-) Maybe THE alternative?

just "only rafter insulation" combined with "only 4.0m eave height" to then waste valuable 24-30cm intermediate rafter insulation and thus additional headroom is crazy - isn’t it?

In the planning process, these things only appeared one after the other, and we tried to find a solution with the manufacturer. The structural possibilities and limitations of this manufacturer result in the parameters mentioned above. At least if we want to stick with the log wall, which is our wish. We especially like the charm of the exposed roof truss – and when we "fell for it," all these problems that came up during the planning process were still far away...

We like the basic concept, but of course, it has unfavorable limits for us – and as already said: The development plan is not responsible for the manufacturer’s restrictions.

The "additional cost" for KfW40 (although I don’t know what the reference value is) is around 10,000 euros. Although they would even be NH certified.

Just read today that there might be funding of up to 100,000 euros for KfW40 even without NH? Does anyone have more detailed information? I haven’t found anything yet... It would be worth calculating it in any case.

I dug out the Stommel catalog... The Blaufichte 01 house (142 sqm) for example is listed on an insert with prices from June 2022 at 241,000 as a shell house, 343,000 almost turnkey (whatever that is supposed to mean), and 400,000 for turnkey. The floor plan is similar in dimensions to ours, just with a different internal layout. They don’t have log walls but work with cork insulation and exposed beams – we’ll definitely take a closer look at that. However, the catalog doesn’t provide much insight, so probably only a personal conversation will help – let’s see if I can get someone on the line tomorrow. I’m currently stuck at home anyway, so I have a little time. Thanks anyway for the suggestion to take a closer look at it.

I see here a conceptually stuck floor plan, imho. It will be difficult to achieve 100% satisfaction as long as the ratio of knee wall to floor area is not internalized. The lower the knee wall, the larger the ground floor must be in order to design functional rooms on the upper floor. This often leads to the realization that it is sometimes more economical to include some rooms, such as the bedroom, in the ground floor. Otherwise, the house is unnecessarily inflated. Or one has to implement the expensive emergency solutions like dormers, which then end up being more costly overall than simply enlarging the floor area.

I see here an in my opinion conceptually stuck floor plan. It will be difficult to achieve 100% satisfaction as long as the ratio of knee wall to floor area is not internalized. The lower the knee wall, the larger the ground floor must be in order to design sensible rooms in the upper floor. This often leads to the realization that sometimes it is more economical to include some rooms, such as the bedroom, on the ground floor. Otherwise, the house is unnecessarily inflated. Or you have to implement expensive makeshift solutions like dormers, which are overall more expensive than simply enlarging the floor area.

We have just developed an idea for this... but the little son has to go to bed. It is a great idea that would still be feasible within the building envelope. For the outdoor area, we would then have to calculate carefully again.

Roughly sketched in writing: enlarge the house along the north-south axis by 2.00 m so that the guest WC can be moved to the east side, all the way to the northeast corner, leave the stairs in place and thus avoid the dirty area; under the stairs, the utility room door might even still be possible. Then create a room about 4x3.70 m in size on the northwest side using the gained 2 meters plus the 2 meters without the guest WC – the rest of the ground floor could remain the same. On the upper floor, use one of the two additional meters in the bathroom as a sloped ceiling area so that the actual bathroom layout can start at a height of 1.30 m. Extend the southeast room to the corridor wall (extended bedroom wall) and let the actual children’s room run the full north-south length at 3.70 m width. In the southeast room, as originally suggested by Elefant, the dining nook could indeed be assigned to a room as a captain’s gable.

I wouldn’t need Velux windows like that, since I could implement enough window areas on the gable sides.

Is that roughly what you had in mind? Or did I misunderstood you? In this variant, one would have to check whether these 20 sqm more floor area are actually more economical than multiple gables and roof windows.