5.5 hours of conversation. Diffusion open or closed?

The financial difference between 70 & 55? Good question, but we want to be independent from electricity and gas, that's why we also have a heat pump and photovoltaic system. This already achieves KFW 55, if the masonry and so on fit.

I refer here to my post #34 in the thread .

At the time when you need your heating the most, your photovoltaic system produces the least.

Monolithic means stone on stone or what is colloquially referred to as a solid house.

Your house will probably not be independent of electricity and gas in the next few years, or how do you want to operate the heating and produce hot water?

A micro combined heat and power plant might possibly be suitable for this. It has an efficiency of almost 90%. However, it must be operated with gas. The investment costs between €15,000 and €25,000.
As a calculation example, however, older houses with high gas consumption are always used. Whether this investment is worthwhile in new construction...?

I recommend purchasing expertise in the form of an expert. You will certainly need one when building a house and he can already advise you today on the choice of the developer, wall construction, etc.

It is worth determining the costs between Kfw70 and 55. Calculate additional investment plus interest costs! Maybe the difference is so high that you will not be able to heat out this investment during your lifetime.

If you have a lot of time and feel like getting proper muscle soreness, yes . We had the same issue here, could have saved around 5000€, the material would have been delivered. But the 5000€ were really worth it to me. Although it should be noted that we used 15mm Fermacell boards. In large format, one person alone cannot lift them.

Conclusion: You need at least two people to work on it, and even then it's backbreaking work. Anyone who has never done this before should stay away from it unless they have a lot of time and a lot of help.

I agree. Especially with the ceiling, you can quickly reach your limits.
A drywall panel measuring 2.50 x 1.25 x 1.00 already has a substantial weight. You have to get the panel up to the ceiling and hold it there until it is properly screwed in. For that, you need at least 2 additional people or some kind of lifting trolley that brings the panel up to the ceiling and presses it there (this was discussed here some time ago).
It may be different with ceiling panels. These are handy enough for self-installation. If you like it. My parents have them in the attic. We didn't want them.

First of all, sorry, I must have misunderstood something regarding the expert.
So you mean to find an expert and go to the house builder with him or lay the documents on the table for him?

Independent of electricity and gas, I meant:
Photovoltaic system on the roof, this feeds electricity into the heat pump and this heats the hot water.
So I don’t need gas at all and electricity only when it’s dark and the photovoltaic isn’t producing anything.
How about an ice storage tank? Costs/benefits

Regarding photovoltaic, it’s not worth it, have others had the same experience?
Doesn’t it also always depend on where you live in [D]?

I only got around to calling a local provider today about solid construction, who said I’d have to find an architect first, who then does a tender so that I can then commission the company and they can tell me what it costs.
But if I do that with a few, it will cost me several hundred euros just for the information, right?

Regarding photovoltaics, it’s not worth it, have others had the same experience?
Doesn’t it also always depend on where you live in Germany?

I didn’t say that - then read through the entire linked thread. I’m actually rather in favor of photovoltaics - I didn’t decide for it for no reason. But I had to realize that the winter months bring much worse yields (hardly any yields) than expected.
However, it is a false assumption that during late autumn, winter, and early spring photovoltaics can largely power your heat pump. This doesn’t work.

Yes - it partly depends on where you live. However, this is not the decisive factor within Germany. Let it be a difference of max. 5% in yield.
Regional differences would be decisive between northern Norway vs. Italy.
By the way: We live in the Saar/Moselle region. Snow in winter is rather rare here and often there is more sun than in other parts of Germany (except for the föhn region). But last week or even the entire January you could more or less throw that regional advantage in the bin.

Moin Moin

once again about the wall construction.
what I find missing in both and would be a deal breaker is an installation level.
I would also separate thermal insulation and weather protection
in timber frame construction by an air layer.

Our wall construction from inside to outside, for example, looks like this

- GK 12.5 mm
- OSB 18 mm
- Inst. level 60 mm mineral wool
- OSB 18 mm
- studwork 240 mm mineral wool
- wood fiber board 60 mm
- counter battens / ventilation 40 mm
- facade cladding FunderMax Trespa or Rockpanel

Olli