KfW 70 - 36er Ytong - Ventilation system

Depending on 10-15 years, the ducts must be cleaned... and all ducts before the filters every 2-3 years

The butterfly valves then as needed...

Hello, I spoke with a construction company yesterday, I don't know if I am allowed to mention the name, but the wall structure is styrofoam block with a concrete core. I was told that a ventilation system is MANDATORY to meet the KfW70 standard!?!? With another construction company using 36.5 Ytong, there was never any mention of a ventilation system!?! What is correct now?

None of those who can make a statement about it???

Nothing and all of it is true, because it always depends. Do the Styrofoam blocks have a concrete core?

None of those who can make a statement about it???

Nothing and all of it is true, because it always depends. Do the Styrofoam blocks have a concrete core?

Yes, they have a CORE.

And what does that mean now? Is there a regulation or obligation?
Apart from the sense or nonsense of a system.

Good evening,

Hello, I spoke with a construction company yesterday, I don't know if I am allowed to name them, but the wall structure is Styrofoam block with concrete core.

So a "squeaky house," as we call it internally in the industry

I was told that to meet the KfW70 standard, a ventilation system is MANDATORY!?!?
With another construction company using 36.5 Ytong, there was never any mention of a ventilation system!?!

What is true now?

There are two possibilities – the salesperson is a donkey or, more likely, he simply lied to you because he couldn’t bring himself to tell the truth. There is no obligation to install a ventilation system; not yet anyway. But that does not mean that it is not strongly recommended with the competitor’s wall construction.

Rhenish greetings