ᐅ Is it possible to install a gas condensing boiler that meets the KfW 55 energy efficiency standard?

Good evening,

we currently have an offer for a prefab bungalow. The seller suggested installing a gas condensing boiler instead of an air-to-water heat pump. This is the more cost-effective option. It is supposed to still meet the KfW 55 standard and qualify for the €18,000 (approx. $18,000) subsidy.

Has anyone had any experience with this?

Grant or no grant. How big is the cost difference? In my opinion, electricity should come before fossil fuels. It’s also an ideological question…

I have already looked into that as well. We would prefer a gas boiler to avoid having that awful unit in the garden....
General contractor 1 says it’s not possible with a KW55 (component-based passive house standard) and doesn’t install it...
General contractor 2 says it’s no problem if combined with solar thermal, ventilation, and heat recovery; the cost would then be similar to a heat pump...

But I’m not sure what is correct....
Gerddieter

Basically, it is possible to calculate that. However, I would generally recommend a heat pump.

If only the outdoor unit is an issue, I believe there are also air-to-water heat pumps without external units. Or how about a deep borehole or trench collector?

RotorMotor schrieb:


If only the unit outside is a problem, I believe there are also air-to-water heat pumps without outdoor components. Or how about deep geothermal drilling or a trench collector?

I think indoor installation can become quite noisy very quickly or get pretty expensive (soundproof door, etc.). Deep geothermal drilling would be great but would exceed my budget...
Best regards

There are also attractive casings available for the outdoor units.