Acceptance of single-family house: energy certificate

We are owners ourselves; the planning and construction are managed by a construction planner/supervisor (planning, coordination, KfW, etc.)

Then you are definitely responsible. What does the person who did the energy calculations say about it? That would be my first approach, followed by the energy consultant (unless it is the same person).

When (approving the) building application, the energy certificate usually cannot be available yet.

Why not? All materials and the construction are known, it's just a calculation example... Ours is ready along with the construction planning.

The issuer of the certificate confirms that the construction was carried out exactly as originally planned and calculated.

So if the person does not have a Delorean in the garage, it is not possible to issue an energy certificate as long as the house has not been fully completed.

Well, it will probably be done that way anyway.

Well, it will probably be done that way anyway.

People also drive too fast on Germany's roads. And there is shoddy work done in construction. Does that make it better or even right now?