Differences of wooden houses

Polystyrene, any kind of foil etc.. in and on the walls.

You will not be able to do without foil (at the latest on the roof). Otherwise cellulose insulation, rock wool, hemp, flax, wood fiber boards, among others. In timber frame construction, Kfw 40 is one of the easiest tasks. Difficult not to reach at least 55. In solid construction, there are also alternatives to polystyrene. Phenolic resin insulation, rock wool, ventilated and cladding wood facade with appropriate insulation, monolithic. It is just more difficult than in timber frame construction.

Just saying, the guy explains it really likeably and well. That's how our Zimmern would build too.

[MEDIA=youtube]GA8liPBdC8g[/MEDIA]

Hi,

our KfW40 house is being built almost without "plastic" (correct: plastics).

Even under the roof, no foil is planned. The airtight layer is in the walls, the 10cm solid wood wall (cross-laminated timber).

On the outside, there is 8cm wood fiber insulation board as a plaster carrier board. Behind it is currently still 20cm mineral wool (which is glass as a raw material). We are currently having the construction company calculate whether blown insulation, as originally planned, might still work. The architect had necessarily calculated mineral wool because my living unit is so small and thus has an unfavorable room/surface ratio. But the head of the construction company is bothered by this and is persistent in a good way. If it is deemed good (calculation) and also remains affordable, it will thus become a bit more ecological.

Under the roof, we use OSB4 instead (which contains more glue than OSB3 and is therefore airtight).

Of course, there will be some pieces of adhesive tape to seal breakthroughs/pipes. But no entire layer of plastic.

Under the floor slab, XPS could not be avoided for cost reasons. An alternative of foam glass gravel would have become disproportionately expensive.

Just briefly about your OSB boards. Over the weekend, we were at a prefab house center again for the first time in a long while, just to gather a few floor plan ideas.
There we came across an architectural firm that builds with Massiv-Holz-Mauer® with air grooves. So completely without glue and so on.
I have to say that I might also be a bit susceptible to controlled uncertainties.
But there even the timber frame construction from the video above was "demonized" because of glue in the OSB boards, and they said you might as well just work with polystyrene.
Also, the controlled residential ventilation in their show house was reportedly switched off after 2 years due to "hygiene." Basically all unnecessary.
Price-wise, it probably plays in a different league anyway, so I didn’t go into it any further.

However, the whole ventilation topic still doesn’t really let me go. Something I would have considered even during the planning phase with Ytong construction would possibly be a solution for my conscience and wallet = window rebate vents everywhere + decentralized exhaust (or only bathroom exhaust?) in bathroom, guest WC + utility room. The advantage I see is that at least some air could circulate and it can also be easily dismantled or deactivated if it really isn’t necessary, which I assume. Because if I have a central or decentralized system for a lot of money, I will go nuts at the slightest fan humming/noise and draft, I just don’t like that. And then only running it at level 1 for the soundscape, the window rebate vents probably handle that amount anyway!?

That’s just my assumption, feel free to criticize or help.
Thank you very much

Again, timber frame construction is also possible without OSB in the wall structure....

But I hardly believe that I can/may explain to any carpentry company what they have to install [in brackets]. The direction for all of them is probably more like, either this way or we leave it, which I would understand. But what would be your alternative? I just wanted to point out how other GCs see it. Whether and how we want to have the whole thing carried out is still (almost) completely open.