As nightdancer just wrote. What matters is not whether the individual components are suitable for KfW55, but whether the provider is currently stable and also able to certify to the KfW Bank that the house as a whole achieves KfW55.
Do not forget the security rating of the door.
And have you already reviewed the standard; what kind of tiles / sanitary fixtures are basically included in the standard.
Yes, I already have the building envelope and the KfW55 standard on my radar and need to look at it in detail. The provider advertises a KfW55-suitable envelope. That this has no significance regarding possible funding is clear to me.
Door security rating: not specified, only a 3-point lock is mentioned --> I'll keep that in mind
Tiles: floor and wall tiles up to 30/60 or 50/50 cm – however, material costs only up to €35/m², which might be tight.
Sanitary: various series from Keramag, Duravit and Villeroy & Boch are included here, Geberit toilet actuation