Well, the concept was set up by the developer. The heating engineer is just the executing subcontractor here who just puts on a brave face. But the client and paying partner in this case is the developer, and what they want is what gets done, even if there are better solutions. But even the average heating engineer in a single-family house doesn't necessarily have an interest in installing the most efficient heating system for you. That usually means extra effort, which he doesn't always get paid for. He also doesn't have the time or desire to come by for 5 minutes every two days over one to two weeks for a thermal balancing. Therefore, what's often installed is what works, causes as few warranty claims and follow-up visits as possible, and is inexpensive so that the customer also awards the contract. Of course, there is also the brand Heizi, which considers itself the ultimate authority and simply does not accept other expert opinions. Mind you, much of what is posted here by laypeople was not invented or cobbled together by them but extensively discussed in relevant forums by experts and also planned, among others, by engineers. Does local/district heating or a gas boiler work in the sense that it heats? Sure! Is it medium- to long-term one of the most efficient systems that should be installed in a single-family house? In my opinion, no.