Can a gas condensing boiler be built to KFW-55 standard?

With us, KFW55 also worked in combination with a gas boiler, but we also have 9 sqm of solar thermal energy. We absolutely do not regret this decision because:

- Lower initial cost
- No annoying "box" outside
- From May to September, we cover the entire hot water demand with solar thermal energy
- The monthly cost is €35 for gas (although in winter we still heat the ground floor with a wood stove).

All neighbors who have heat pumps have significantly higher monthly costs, which is partly due to the fact that they - because of small children who often bathe - have a lot of peak demand. The cost for construction drying with a heat pump in the neighborhood averaged €3,500. For us, it was just €500.

Yeah, I would still install gas where possible. I also find the outdoor units incredibly ugly and depending on the installation location, they can be acoustically annoying. In the next 10-15 years, the heat pump won’t make up for the additional costs. After that, you can still consider switching.

Please also think a bit about the environment. Current events show that we should not continue like this.

Please also think a bit about the environment. Current events show that we should not continue like this.

The topic can certainly be discussed controversially. At the moment and also in the medium term, electricity is simply not yet green. Partly I operate a heat pump with coal. At the same time, my gas heating has a consumption of about 1/6 of what my parents use in their 90s terraced house with a smaller area. Generally, with a new building, well insulated, heat recovery in the ventilation system, you already do a lot for the environment. The mix of very low gas consumption, low electricity consumption (LED lamps everywhere, etc.), a garden designed to be beneficial for helpful insects, etc., certainly does much more for the environment than the typical old building resident could do. We also don’t have two 300 hp SUVs parked in front of the house, so I think everything is fine in that respect.

Please also think a bit about the environment. Current events show that we should not continue as before.

If you consistently think the idea through to the end, you can really only come to one conclusion: Do not build new. The heat energy demand of a new building is downright ridiculous compared to the grey energy. But you just can't position yourself ideologically so well with that.

The old argument of the heat pump powered by coal-fired electricity can be easily refuted by the fact that even then less CO2 is emitted than with the gas heating. ;)