Installation of a gas heating system in new construction 2023/2024

Actually, it doesn't really matter whether it helped, since it was no longer necessary at the time. It was clear judicial misconduct. Infection fatality rate at flu level. Hospitals without an increase in intensive care occupancy, reduction of beds. Well, the review will take a long time if I look at the level of knowledge of kathi and co here.

Or we better focus on the climate pig that is being driven through the country

Well, the image title is at least misleading. They write "don't know if it helped," but the correct phrasing would be "don't know how much it helped." That's already an important difference. One statement is verifiable, the other is incendiary nonsense.

Exactly, then we're back to categorizing texts from the fringe of the spectrum.

I have actively participated in the discussion here myself, but we should slowly come to a conclusion and give the OP an answer.
The draft law can be googled and I came across a few things that should be considered if you are in the OP’s situation (or similar). I did not specify the exact articles and paragraphs as sources now, but if someone wants to check for themselves, please simply use Ctrl+F.

[*]"If the owner entrusts the heat or hot water supply to a contractor, both the owner and the contractor are subject to the obligations regarding the requirements for the condition of heating systems or other requirements for the building or an efficiency status according to § 8 paragraph 2, as a contractor acts on behalf of the owner."
-> so developers, general contractors and/or heating installers must also be liable for this. Therefore, it is best to coordinate with them once. I can well imagine that a company will not want to take any risks here. Maybe an agreement on the additional costs can be reached.

[*]"If a conversion of the gas distribution network to hydrogen is planned by December 31, 2034, the building owner may install a gas heating system that burns both gas and hydrogen. In this case, they are obliged to source 50 percent green gases (gaseous biomass or green or blue hydrogen including derivatives produced therefrom) from January 1, 2030, and 65 percent green or blue hydrogen from January 1, 2035."
-> It may be worthwhile to speak with the municipality/the local utilities once. If something like this is planned, then that would also be an option.

[*]"The installation of heating systems based solely on fossil energy sources – especially gas and oil heating systems – is no longer permitted as of 2024." and
"The enforcement of the regulation is ensured upon installation of a heating system in a building to be erected within the framework of the declaration of fulfillment according to § 92 paragraph 1."
-> There we have the answer that was being sought. Inspection takes place when the heating system is installed, not as part of the building permit. I did not find a transition period in the law.

1. What happens if the heating system is installed in October 2023, but the house is only accepted in February 2024?!
2. What happens if the heating system is only installed in January 2024 and the house is accepted in May 2024?!

To answer the questions directly as well:

[*]Everything is fine here. Gas heating is OK.
[*]You are in trouble and have to replace the heating system.

The decisive date is the installation of the heating system. Generally, however, to avoid any risk, I would switch to a heat pump. Since your general contractor/developer is also liable, you might be able to reach an agreement with them.
It is also currently not foreseeable how high gas prices will be in, for example, 15–20 years. It is also quite possible that the gas network will be shut down or converted to hydrogen in 20 years. If you decide on a gas heating system, then make sure that it can be operated 100% with hydrogen.
Personally, all of this is too uncertain for me and I would opt for the safe solution.

But it is and remains a draft. The final law may turn out completely different, especially since Habeck himself is facing considerable headwind from the [Ampel]. Conclusion: At the moment, no one can give a binding answer to this.

But it is and remains a draft. The final law can turn out quite differently, especially since Habeck himself is facing considerable resistance from the traffic light coalition.
Conclusion: At the moment, nobody can give a binding answer on this.

Logical. That is of course clear. But the OP had asked, and in that or a modified form it will certainly come. I only gave him the information that the draft provides, as well as my assessment of it. In the end, the decision has to be made by the OP himself.