ᐅ KfW 40 or better in solid construction without additional insulation possible?

Hello,

I was initially set on a timber frame construction for my future house. However, I am now reconsidering solid construction because it does have its advantages. Ideally, I would prefer this without additional external insulation, as that would be redundant and insulation typically does not last as long as the masonry itself. Poroton seems the most appealing option to me at first glance.

But is that even feasible? Are there bricks (or other solid building blocks) that on their own meet the KfW 40 standard, or possibly perform even better?

Does anyone have experience with this? Has anyone actually built something like this?

I’m open to discussion if you believe additional insulation makes sense. However, no “Styrofoam” will be used on the exterior walls; if anything, it will be an alternative material.

The comments I would rather avoid are those suggesting a lower energy standard would be sufficient. I will not build anything below KfW 40.

Thanks in advance for your input.

Best regards,
Specki

Are you planning a basement?

If yes, then you don’t need to read any further. In my opinion, KfW 40 standard and brick without insulation don’t work with a basement.

If no, then probably only with insulated 42cm (16.5 inch) bricks.

With monolithic construction, it becomes difficult. The wall will be very thick, and the blocks are expensive.

If EPS (expanded polystyrene) is not an option, how about a double-layered sand-lime brick wall with mineral wool insulation in between? The outer layer could also be sand-lime brick with plaster or as facing bricks.

No, no basement planned. Just an insulated slab-on-grade.

If it is double-layered with mineral wool in between, there is again the risk that the mineral wool might eventually fail. I’m not sure, if moisture gets in, or pests.

Maybe I have the wrong idea. And a well-designed ventilated exterior insulation system using mineral wool or a natural insulating material can easily last 80 to 100 years?

Yes, that will easily last longer than you. However, monolithic construction also works.