Since the funding has unfortunately expired, I would be interested to know what is more sensible. KFW 55 or rather KFW 40. Is there a significant financial and structural additional effort between the two? Does anyone have experience with this? We are currently facing the decision of which standard we should choose.
In practice, one will hardly have this decision, as for timber frame panels it basically means "surcharge for U-value tuning with - other or thicker insulation materials - essentially the same wall construction," and for masonry it generally means switching to ETICS and often also a different brick in the structural masonry shell. Bricklayers sell KfW40 wall constructions less frequently, thus with less routine in execution, whereas for the timber framers the basically identical wall construction in the connection details is more or less only scaled.