ᐅ Additional cost for KfW 70 energy standard

Created on: 11 Oct 2014 09:59
I
iomaju
Hello everyone,

We are about to decide whether provider A or provider B will build our house. The design is exactly the same for both houses, with the difference that House A is equipped with a Dimplex air-to-water heat pump installed indoors and meets the KfW 70 energy standard. House B has a Viessmann split air-to-water heat pump and does not meet the KfW 70 standard. My advisor told me that the additional cost to reach the 70 standard would be around 7,500 euros.

How do you assess this? Both houses will be built with solid 36.5cm (14.5 inches) Poroton bricks.

Thanks in advance for your answers!

Best regards
I
iomaju
13 Oct 2014 12:44
therefore, "my mistake" 😉
These are aerated concrete blocks with the specified insulation values. This is stated in the building and performance specification...

Regards
Jochen10413 Oct 2014 12:54
Hello,
could it be that you are confusing the U-value W/(m²K) with the lambda value here?

Best regards
Jochen104
V
Vega82
13 Oct 2014 13:01
Looks just like it ....

U-value = 0.23 W/(m²K) with a lambda of 0.09 should generally be sufficient for KFW70.
I
iomaju
13 Oct 2014 13:09
uuhhh. absolutely. next time I’ll do some research before asking something 😕
So: 0.23 W/(m²K) if the lambda is 0.09
to
0.27 W/(m²K) (which probably isn’t sufficient for KfW 70)

🙂
V
Vega82
13 Oct 2014 13:14
That’s probably the case.... with 0.27 you won’t get there; as I mentioned, much more counts than just the exterior walls.
V
Vega82
14 Oct 2014 10:01
Why was my link about achieving KFW with aerated concrete deleted?



Hello,

is it because the forum rules do not allow it?

Regards, Bauexperte
Bauexperte