New building KfW55 with gas, solar, and controlled residential ventilation with heat recovery

Hello XeNiA, we are also leaning towards gas+ST+controlled residential ventilation as KFW 55. Our contact person at the general contractor is sure after consulting "his" energy expert that this will work with additional insulation. Have you made any progress?

If you build with facing bricks, is there enough insulation in between at all?

I believe this is less a question of what is technically feasible and more of the cost. According to information from the KS association (we would like to build the wall with KS), a U-value of 0.16 with core insulation is possible either with 0.024 W/mK (d=14 cm) or 0.032 W/mK (d=18 cm).

For d>14 you then need special masonry anchors for the facing shell. KS and facing bricks are of course a great combination.

Hello XeNiA, we are also leaning towards gas+ST+controlled residential ventilation as KfW 55. Our contact person at the general contractor is sure after consulting with "his" energy expert that this will work with additional insulation. Have you made any progress?

We haven't made much progress yet, unfortunately.
So far, everyone agrees that it is definitely possible with additional insulation.

Hi XeNiA,

we will also be building soon and aiming to achieve KfW55, we prefer gas for heating. The general contractor informed us that KfW55 is possible with gas (ST+ventilation). However, it may be that we have to use a 20cm stone plus insulation instead of the monolithic construction (36.5 cm aerated concrete). We can live with that...

An energy consultant will soon look into this and say how it can be realized.