ᐅ Is this wall insulation setup suitable for a KfW 70 energy-efficiency house?

As I said, I am not an expert but I am happy to share answers when I have them. There was a building proposal available, and I can still make changes. If anyone has tips, I am grateful for any help. Most people even kept the 12.5 cm (5 inches) insulation. Maybe advice on whether the insulation is okay or should be changed. There is still time for that. Thank you.

I assume you are building with a general contractor. Therefore, my only advice is to involve an independent expert. This may cost a bit upfront but will pay off in the end 🙂

And no one can tell me whether the wall structure with the insulation, heating, and triple-glazed windows on 17.5cm (7 inches) Ytong blocks is any good? I can hardly give the advisor more information anyway. 😕

Hello,

Livestrong schrieb:
...Since I value good insulation, I was advised to use 16 cm (6 inches) and triple glazing.

What criteria do you use to define “good” insulation? You could just as well choose 20 cm (8 inches) with double glazing, or 18 cm (7 inches) with triple glazing, or other combinations.
You don’t have any benchmark to evaluate the effect of better or worse insulation.
Only an energy consumption forecast based on the actual building parameters, climate location, and user behavior can help here (not the energy saving ordinance or KfW certificate!). The efficiency of the heating system and domestic hot water production (technical solution) also plays a significant role.

Livestrong schrieb:
...If anyone has tips, I’m grateful for any help here. Most people have even stayed with 12.5 cm (5 inches) insulation....

Most people usually don’t really know what they actually bought, as they blindly trust a skilled and trained salesperson! Many only face unpleasant surprises afterward.
Partial thermal insulation combined with additional insulation is not unproblematic from a building physics perspective! Therefore, the choice of additional insulation material is quite limited.

I can only support E. Curb’s suggestion to consult an external expert (building and building services engineering)!

Best regards

I understand what you mean. I would like to do a lot more, but the house construction happened very spontaneously, and the plots were taken right from under my nose, so everything had to move quickly.

The house with the standard equipment should already meet KfW 70 standards.

What I want is clear: not too hot in summer and not too cold in winter 😉 Aerated concrete is supposed to handle this well. Since it is a semi-detached house, each side has its own wall, and between them there will be an Isover soundproofing wall.

Of course, I could add 20 cm (8 inches), but then I would be approaching passive house standards, which I don’t want. 12.5 cm (5 inches) is not much, so I opted for 16 cm (6 inches). 18 cm (7 inches) would probably only add minimal improvement. At some point, I have to make a decision. I really appreciate your help, but now I’m more looking for a straight answer like: This is quite solid or total rubbish, forget it 😉 Of course, everything can be done better. Thanks 😉

Livestrong schrieb:
.... but the house construction was very spontaneous and the plots etc. were taken right from under my nose and then it had to go fast.

This is already the first problem with the project. "It has to go fast" is the best recipe for a money pit. An old sales trick.

Livestrong schrieb:
.... The house with the standard equipment should already meet kfw 70.

Not uncommon that this is only on paper. In reality, such properties sometimes do not even meet the energy savings regulations standard.

Livestrong schrieb:
.... What I want is clear: Not too hot in summer and not too cold in winter 😉 Aerated concrete is supposed to be good for that.

You can take a very different view on that. Also, subjunctives rarely become part of a contract 😉

Livestrong schrieb:
.... therefore 16cm.

Since this seems like rolling dice, I’d say go with 14 cm (5.5 inches), because 16 cm (6.3 inches) only brings marginal improvement. (what?) :o

Livestrong schrieb:
.... but what I really need now is a phrase like: This is quite solid or total rubbish, forget it 😉

Then I’d say, just by how this was started, it’s total rubbish.

Best regards.