ᐅ Insulation for KfW 70 Standard – a quick question

Created on: 4 May 2015 13:42
S
SimonMoers
The developer states this in their building specification:
17.5cm (7 inches) sand-lime brick with approximately 12-16cm (5-6 inches) external thermal insulation composite system (ETICS) with a thermal conductivity of 0.035 W/(m·K).
Is this sufficient, or is it simply the most cost-effective solution?
M
maximax
13 May 2015 17:51
Yes, I’m a fan of bunker-thick walls 😉

Thicker walls mean better thermal storage (although sand-lime brick is probably less critical in this regard), improved sound insulation, and fewer issues when chasing for pipes or cables (or fewer problems if these were chased incorrectly).
B
Bauexperte
14 May 2015 10:55
Hello,
maximax schrieb:

Thicker walls mean better heat storage (although sand-lime brick is probably less critical in this regard),
**Heat Storage of Sand-Lime Brick[B]:**

Due to the high thermal conductivity of exterior walls, additional thermal insulation is essential to meet the requirements of energy efficiency regulations (building permit / planning permission).
maximax schrieb:

better sound insulation
**Sound Insulation[B]:**

Sand-lime bricks have a very high bulk density and are therefore very heavy. This gives them excellent properties in terms of sound insulation. As they are also highly compressive strength capable, thin, highly load-bearing walls with very effective sound insulation can be built using sand-lime bricks.
maximax schrieb:

and fewer problems when chasing for cables (or fewer problems if the chasing was done incorrectly).
How to properly chase is defined by technical standards and – as expected – by the relevant DIN standards.

So, more isn’t always the ultimate solution 😉

**Source: my website

Regards, Bauexperte
M
maximax
14 May 2015 11:55
Bauexperte schrieb:
Due to the high thermal conductivity of exterior walls, additional thermal insulation is essential to meet the requirements of the energy saving regulations.

I was referring to thermal storage. The more mass a building has, the longer it stays cool during a short heat period, and the longer it takes for the house to cool down if the heating fails. Of course, sand-lime brick with external thermal insulation composite system (ETICS) is generally better in this regard because almost the entire mass is insulated on the outside, whereas in a monolithic structure, almost half of the mass remains uninsulated.
How to create "chases" is defined by the technical regulations and – as usual – the DIN standards

...and which all on-site laborers and DIY builders always precisely follow in the best-case scenarios envisioned by homeowners.

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