ᐅ New Single-Family Home Built to KfW55 Standard – Which Heating System to Choose?

Hello everyone,
I have read many articles and would now like to benefit from the extensive knowledge of the members here.

A brief overview of my building project:
- Single-family house with approximately 160sqm (1,722 sq ft) of living space
- No basement, 2 full floors with an unfinished attic
- Relatively large window areas and an open-plan design with a staircase in the living area
- Underfloor heating throughout the house with tile flooring
- KfW 55 standard with timber frame construction
- A wood-burning stove will be installed

Unfortunately, I have little experience in this area and rely on recommendations from others regarding heating.
On the ground floor, we have a utility room of 8sqm (86 sq ft) where we would like to accommodate all the technical equipment.
The builder recommends installing a central ventilation system, which we would like to do.

Now to my question:
There is a gas connection in our building area, and a friend told me we should definitely heat with a gas boiler. To meet the KfW standard, according to the energy consultant, we still need to install 9sqm (97 sq ft) of solar panels on the roof.
A heating engineer friend advises: choose an air-to-water heat pump – split system Weishaupt LS 8-BREK – so you can avoid the solar requirement.
I have requested quotes for both options from different heating engineers, and they come out roughly the same in price.

Since I have heard many statements opposing air-to-water heat pumps, I tend to prefer gas.
However, the main challenge is the limited space in the utility room. In addition to the heating system, the two-flue fireplace, and the ventilation system, the electrical control cabinet as well as the washing machine and dryer are also planned to be located there.
Is there anyone who has faced a similar space issue?
What would you recommend?

Thank you very much in advance for your help.

Schraube348 schrieb:

Since I’ve heard many opinions here against an air-to-water heat pump, I would prefer gas.

Why? I would definitely avoid gas and go for a heat pump instead. Install a photovoltaic system rather than solar thermal.

We will have a similar situation, also including a wood-burning stove, and we are still undecided. I have had a solar system before and, to be honest, I no longer believe it was a truly worthwhile investment back then.

Currently, we are leaning towards a heat pump split system (this has been recommended but not yet fully considered) and will soon explore photovoltaic systems; at the moment, this makes sense for us.

In the end, both options provide heating and each has its advantages and disadvantages; it’s not just about the numbers. I wouldn’t like the idea of having a token solar system installed on the roof without a clear and reasonable purpose behind it.

Maybe a heat pump split system would be smaller to install? (I am a layperson in this area).

The location and noise of the heat pump are major concerns for us and worry us somewhat.

Have you also taken into account that you might be eligible for a subsidy or grant for the air-to-water heat pump when comparing prices?

Traube348 schrieb:

The main issue we have, however, is the limited space in the utility room.

How about a Panasonic monoblock, for example? That way, there is no indoor unit.

Don’t agree to anything else. If a gas connection is available, there’s not much to consider. It’s the most economical and reliable heating method, even for new builds.

Ventilation is nice to have, but not necessary. It’s more about comfort.

We have an air-to-water heat pump and ventilation system. We’re satisfied. However, air-to-water heat pumps are still a long way off for most heating installers, and you need to invest a lot of time learning about the technology yourself. There are still residual risks in terms of durability and energy consumption.

That said, there are advocates of air-to-water heat pump technology here who will probably criticize me heavily for this...