ᐅ What are the advantages of 24mm perimeter insulation?

Created on: 12 Jul 2020 11:29
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Smarti99
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Smarti99
12 Jul 2020 11:29
Hello,
My entire foundation slab is above ground level. On top of that, there will be Poroton blocks and a floor construction 20 cm (8 inches) thick.
Would I gain a significant advantage if I insulate the 24 cm (9.5 inches) perimeter of the foundation slab?
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michert
12 Jul 2020 11:55
You can now achieve an insulation standard that you would later only reach by sacrificing ceiling height. -> Thicker insulation on the structural floor.

Whether this will ultimately pay off after xx years is a completely different matter. Without subsidies or incentives, this will likely be financially worthwhile in very few cases.
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Smarti99
12 Jul 2020 12:12
I mean on the outside of the 24cm (9.5 inches) high side of the foundation slab
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michert
12 Jul 2020 12:15
You need to ask your designer that question. Basically, this area is probably the most sensitive part of the entire house. Because of the concrete slab floor, a thermal bridge often forms in this area. Especially in the base area, you can quickly get condensation and therefore mold.
kati133712 Jul 2020 12:59
We did this because it was the final step to upgrade our house from the standard level to KfW55. This allowed us to take advantage of the subsidized loan. The repayment grant amounts to €18,000, the additional cost for the perimeter insulation was €2,500, and there was an extra €3,500 for the energy consultant. So, the calculation was straightforward.

However, this only makes sense if the house is already built close to meeting the KfW55 standard.
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Smarti99
12 Jul 2020 13:18
KFW funding is no longer available.
I am only concerned with the practicality.

I found this image on the internet and marked the insulation in question with the arrow.
If I interpret the image here correctly, it seems relatively pointless?

Isotherm representation of a temperature field in a rectangular duct with colored scale on the right