General questions about insulation

Hello forum community,

probably some will shake their heads in disgust, but I have to ask some beginner questions. Maybe they have already been answered, but in my brief scan today I found nothing on the subject. Now to the questions:
We want to build a house as the topic here is. Of course an energy-saving house or efficiency house. There are classifications according to Kfw 70, 55, 40. Naturally, the whole thing should remain within budget. I am interested in the required insulation values for the individual classifications. Since the weight increases with thicker insulation, at some point a prefabricated house is excluded. I am currently interested in a solid house with walls made of Duo Therm. But I am not fixed on that. A 30 cm wall has a U value of 0.21. How does the U value of triple-glazed windows compare? And what about the corresponding roof insulation? A table would already help me. Who actually determines the classifications? Or is it all done with the blower door test? The rest is probably standard, so solar panels on the roof and probably an air-water heat pump as well as underfloor heating. And, of course, controlled residential ventilation to prevent mold. Maybe you can understand and expand my fundamental considerations? I just don’t want to compensate for poor insulation with a bigger heating system and on the other hand not spend too much on insulation...

Best regards Axel

Almost 150 hits and no own opinion? What's the reason? Too many questions or the wrong forum?

Since the weight increases with thicker insulation, at some point a prefabricated house is out of the question.

explain this causality...

Certainly, the weight of a component increases with increasing material thickness... but I have never seen the property "weight" as a decision criterion in house construction. Where do you want to build? On a houseboat?

DuoTherm... that didn’t mean anything to me just now. Quickly googled... ah, Lego bricks.

I am now interested in the required insulation values for the individual classifications.

That is derived from the respective terms. Each xx% of the primary energy demand Qp of the corresponding reference house (and a somewhat higher transmission heat loss Ht). Take a look at the Wikipedia article "Energiestandard". The insulation values of individual components are, in my opinion, not tied to maximum values but rather a balanced result from all components has to achieve the Ht value. In connection with the primary energy consumption, the heating technology used then comes into play.

And of course controlled residential ventilation for the mold.

A controlled residential ventilation is neither for nor against mold. A ventilation device in your house primarily ensures the standard-required minimum air exchange rate. Moreover, it is a nice piece of luxury.

Regarding the U-values you mentioned for comparing the requirements of the various KfW standards, I would like to link you an article from an official source... but that is not desired here, so via private message.

Regards ks

Hello Axel,

probably some will shake their heads in disgust, but I have to ask some beginner questions.

Wrong adjective ...

Maybe they have already been answered, but in my brief browse today I found nothing about it.

... that fits better; a "brief browse" just isn’t enough. Also, you write without punctuation ... it’s quite tiring to read.

We want to build a house, as the topic here is. Of course, an energy-saving house or efficiency house. There are classifications according to KFW 70,55,40. Of course, the whole thing should stay within budget ... I am currently interested in a solid house with walls made of Duo Therm.

So "Lego house," as my predecessor writes, or "squeaky house," as I call it.

Already in the first sentences it becomes clear that you have little to no idea about what you want to undertake; a terribly bad prerequisite for building a house ...!

Maybe you can understand and expand my fundamental considerations? I just don’t want to compensate bad insulation values with a bigger heating system and on the other hand not spend too much on insulation...

That brings us back to the beginning of the "brief browse." On the HBF many users have put a lot of effort into posting their experiences. Click through the various forums and work your way step by step towards your house with that.

It’s not enough to be driven by the desire to build a house and to do it as cheaply as possible. By the way, a forum like this cannot close knowledge gaps 100%; but it can offer help towards help. As I read it, you should first seek professional help (also as construction supervision during the actual build). Then the basics/relations of the valid energy savings ordinance will become clear ;)

Best regards

Hello Saneca,

like the two previous posters, I can only recommend that you deal with this intensively and early on. Read in forums, go to trade fairs, visit model home parks and talk to the people from construction companies, banks and providers of individual trades. You will find that you talk to 10 people and get 20 opinions, but with each conversation you become a little wiser and new questions arise for you. In addition, I can also strongly recommend that you look for an independent construction supervisor. And then definitely don’t be dazzled by any internet prices. In some trades you can live with the standard, but in many you want a bit more. Yesterday we went through the sample rooms in advance and there you would like to have this and that is also not bad. And then there are a lot of additional things that are simply not included in the building and service description, such as the typical ancillary building costs but also many other things.

So you know, construction expert, I find it a bit off to just dismiss my questions simply because you don’t like my German and my punctuation. And someone like that is even a moderator here? You should be a role model and not a complainer. And then the typical hints about the 3 L’s (Reading reading and reading). Why don’t you first address my questions like Karliseppel did, then you can also complain about my German. Now to the topic. I gladly admit that I don’t know much about house building compared to you. That’s actually why I was thinking of a prefabricated house. And that’s why I’m here. However, I didn’t know that this is such an elitist circle here, where not even questions get answered. In any case, thanks to Karliseppel for the link in the PM, that gave me some reading material again and will help me avoid further beginner questions in the future. (But somehow I once thought that’s what forums are for?) Best regards Axel