Gas condensing boiler, air-water heat pump, fuel cells - please advise

Especially since with air heat pumps you should always consider the boundary distances to the neighbor. If here it already says "no space for trench collector". But especially air heat pumps require good planning (heating load / pipe network calculation for underfloor heating) and many fail at this. The HB doesn't care, he sells 1 heating unit as requested – done. Planning was never mentioned (the HB earns nothing from that, since an engineering office does it.) In my opinion, air heat pumps are only for people who read up on the topic and then implement everything themselves. That means having a heating load calculation done, having underfloor heating planned, and on that basis then getting a small Asian one (e.g. Panasonic aquaera) + BAFA subsidy – but be careful, you have to find a specialist company beforehand that will stamp it and report it to BAFA upon completion... And that before ordering the Panasonic ;-) Otherwise, air heat pumps are simply overpriced. A commercial air heat pump from the HB quickly costs 10-15k€ complete with accessories. That's just too much... The Asian model is available to the interested home builder for about 4000-5000€. (And from that, the BAFA subsidy of 1500€? Then still gone)

Gas condensing boiler, but without a water-carrying stove. That would be, in my view, the most economical solution.

Good morning everyone,

First of all, thank you very much for your responses.

Regarding the boundary distance to the neighbor, that is not an issue. It is more than 50m away.

My plot itself is 913sqm, but a large double garage will be added, and I need relatively much space for the infiltration of the small sewage treatment plant. Furthermore, along one property boundary runs the supply line for water. I have the obligation not to build anything on the 4m wide strip there. It certainly wouldn’t be cool if the line froze due to my withdrawal rate.

So the gas network is definitely available. However, since I live in the second row and the line does not run directly on my street, I will definitely have to plan higher costs for the line. The connection costs €1400 plus about €30 per meter for the trench. I’m calculating about 50m here. That then comes to almost €1500.

The heating load has already been calculated. It was something around 7kW, and an 8kW heat pump from Vaillant should be used.

2. But leave out the solar thermal system, that should be possible if you have a controlled residential ventilation system with heat recovery.

2. But leave out the solar thermal system, that should be possible if you have a controlled residential ventilation with heat recovery.

However, solar thermal is mandatory when using gas or oil. Leaving it out is difficult - and only possible by replacement, e.g. domestic hot water heat pump. But installing only an oil or gas heating system is not allowed without the renewable energy share....

That is why it must also be used in old building renovations.

Can I leave out solar thermal? I always thought it was a must according to new regulations and then you could choose either solar for heating or ventilation system. I am building with a planning office, meaning all trades will be contracted separately.