Funding application for heat pump in construction project via general contractor

We are currently building a single-family house with a garage, turnkey, through a general contractor. We are getting a heat pump with underfloor heating and would like to apply for the innovation grant through BAFA. The question now is whether we have to submit the offer to BAFA that the installer made to our GC or if the installer must issue this offer in our name. Only after we apply to BAFA may the installer confirm the chosen heating system to our GC. Thank you in advance for the answers!

What is absolutely necessary can only be explained to you with certainty by the BAFA. To avoid discussions, I would request an invoice in my name - either from the installer or from the GU as a separate service (the latter is what we did).

We are currently building a single-family house..

Does that mean that construction has already started? The applications for the BAFA must be submitted before the project begins. Aren't you already too late?

"The application must be submitted before project commencement. Project commencement is defined as the conclusion of a delivery or service contract attributable to the execution."

No, with the general contractor it is only too late when the specific heat pump to be installed has been ordered.

A general contractor contract for "HP from company X of series Y" is not yet the start of the project, as the specific model has not yet been determined, e.g. due to the lack of a heating load calculation.

No, we are not too late. The heating system will only be ordered once the application has been submitted. According to BAFA, an offer does not have to be attached. Only upon request. Now the only question left is the amount of funding. Everywhere it says for new buildings from a certain annual performance factor up to 35% of the investment sum. However, since it always says "up to," I wonder if the 35% are tied to certain requirements and will be reduced accordingly if they are not met.