KfW40 / KfW60

Hello,

we are planning to build a house and are simply not sure whether we should build to Kfw40 or Kfw60 standard. Is it possible to estimate the difference in construction costs, or how is this usually done?

So the KfW40 standard describes better insulation and system technology, therefore consumes less energy, but costs more. The easiest thing would be to commission an energy saving ordinance certificate during the house planning, so you know more precisely which materials are needed and how high the costs are.

Calculate what is cheaper in the long run.

Interest/repayment + energy costs
KfW40: Interest/repayment higher / energy costs lower
KfW60: Interest/repayment lower / energy costs higher

But consider the rising energy prices and otherwise take a look at DIN276.

Does that mean we have no idea here and won't advise you. :D

No, it's definitely right that you get it done by a professional.