How could it be otherwise - Which heating system in the new building

We are currently looking for a property developer. And everyone somehow offers us a different heating system as the non plus ultra.

Planned is:

Detached single-family house with 130 m² living space on a basement. Gas is available in the building area. What we definitely plan is a wood stove (so a chimney will definitely be built).

Planned is at least Kfw 70, if the cost/benefit ratio works out, preferably better.

So far, we have the following options:

1. Gas condensing boiler with solar support for hot water 2. Air-to-water heat pump 3. Air-to-air heat pump

Another developer told us that with pellets (due to the good CO2 balance) we can already achieve Kfw 70 even without solar. With solar, possibly even better.

I know it is difficult to make a "remote diagnosis" since there are many factors. The usage behavior would currently be that actually nobody is at home between 8 a.m. and 6 p.m. during the week. But this will obviously change (once we have children).

We would accept the loss of space in the basement due to pellets or oil if this type of heating system were recommended.

Thanks in advance for your tips / opinions

Hello,

We are currently looking for a property developer.

I hardly believe that, this is more likely about a general contractor!
If you want to build or buy, these differences should be known first.;)

...And everyone somehow offers us a different heating system as the non plus ultra.

Of course, everyone sells whatever they have in stock and that naive builders have to be stuck with.;)

...
Now we currently have the following options to choose from:

1. Gas condensing boiler with solar support for hot water
2. Air-to-water heat pump
3. Air-to-air heat pump

Point 3 is probably nearly 100% wrong for KfW 70, since the heating loads are likely simply too high! => A bottomless pit for the later heating costs!
Point 1 can only be achieved if a solar thermal system, which is usually uneconomical for single-family homes, is "bought along"! Unless the 15% rule is applied, which makes the solar thermal system dispensable.
Point 2 is an alternative, but only if the framework conditions are given for it (including suitable characteristic curves).
Pellet heating works out very well in terms of primary energy (on paper) due to the primary energy factor. End energy wise hardly reasonable, partly due to the high investment!

Best regards.

First of all, thank you.

I had forgotten one point.
A controlled ventilation system with heat recovery should definitely also be installed.

Does this change anything in the recommendations?

...There should definitely also be a controlled ventilation with heat recovery installed.
Does this change anything about the recommendations?

Basically not, this makes the heating load and thus the annual demand (heating) lower. However, the effect is less due to the recovered energy and more due to the controlled ventilation compared to window ventilation.
The recommendation is: first careful and precise calculation (ventilation, standard heating load, room heating loads, heating surfaces), then selection of the appropriate heat generator (manufacturer/device).

Regards.

ok. Thank you.