ᐅ KfW 70 house

Hello.
I have a question for the experts among you.
We are planning to build a bungalow next year to KfW 70 standard.
I have now received my energy certificate. However, the value is 63 kW/m².
The architect had calculated with windows that have a U-value of 1.0.
But we are getting ones with a U-value of 0.8.
Is that a significant difference, or just minimal?

No one has a clue

I simply assume that with the given data, no one can provide any input.

Good evening,

lars.p schrieb:
Hello.
I have a question for the experts among you.
We plan to build a bungalow next year to the KfW 70 standard.
Now I have received my energy certificate. But the value is 63 kW / m.
The architect assumed windows with a U-value of 1.0.
But we are getting windows with a U-value of 0.8.
Is that a big difference? Or only minimal?

What can you even say about that?

A U-value of 1.0 initially sounds like the architect calculated the overall window value, not just the glazing. 63 kW is not great... but the windows will hardly be the reason; the KfW 70 requirement is met anyway. So what?

Regards, Bauexperte

No, the entire window was included in the calculations.
For KfW 70, I need a value of 43 kWh/m² (14 kBtu/ft²).
And if the windows now have a U-value of 0.8 W/m²K (0.14 Btu/ft²·h·°F), does that make a big difference?