Water-bearing fireplace stove floor heating, heat pump, photovoltaic, new construction?

I also wanted to ask something here even if it doesn’t quite fit.

In April I am building a Kfw55 house with 120m², with an air-to-water heat pump and central residential ventilation, and I am currently facing the question of whether I should also have a fireplace installed or not.

Is it sensible to install a stove in case it gets colder in winter so that the heat pump doesn’t have to work so hard?

Or can one safely do without it.

Because with the fireplace there are additional costs, like the chimney and air pressure monitor, etc.

Is it sensible to install a stove in case it gets colder in winter, so that the heat pump doesn't have to work so hard?

Economically, in terms of heating, that is certainly not the case.

: We are also building next year, our house is 160 m², and we will probably opt for an air-to-water heat pump (99% certain) and install a controlled residential ventilation system. We also debated for a long time whether to install a wood stove. Also because many people keep telling you that an air-to-water heat pump is not efficient enough, and I am/was afraid that the house wouldn’t be warm enough in winter, plus all the previous builders in our development have installed a stove, so we thought there must be a reason for that. However, neither of us are really fans of stoves. Yes, the warmth is quite nice, but honestly, we have a stove in our current apartment (which is sometimes used as the sole heating source to keep the oil heating costs down (70s house)) and we are bothered by the dirt and the effort involved with it. We then seriously considered whether we would actually use a stove regularly in the house and if it would be worth the money, which is not exactly cheap... We came to the conclusion that it would be nice now and then in winter, but on a daily basis none of us would be keen on the work and the mess, including carrying and storing wood and so on. It would probably have ended up with the stove being lit once a year at Christmas for the cozy atmosphere and otherwise not being used, to put it bluntly. So we decided against a stove; it was too expensive for us and, in addition, with our floor plan, we wouldn’t have had a nice place for the stove anyway. We prefer to invest the money in things that are more important to us. I hope we won’t regret this decision eventually, but on the other hand, there are surely people who have a stove and don’t use it and thus regret spending so much money on it.

Also because many sides tell you that an air-to-water heat pump is not efficient enough and I am afraid/was afraid that the house will not be warm enough in winter and moreover all previous builders in our building area install a stove and we then thought that there must be a reason for that

Compared to the stove, an air-to-water heat pump should be significantly more efficient. In my opinion, there is only one really meaningful reason for a stove: coziness

A stove costs money, and against occasional coziness stand acquisition, loss of living space, and operating costs... plus there is also the dirt.

In my eyes, this is not in any relation to each other... we consciously refrained from the stove and have not regretted it so far...

If the air-water heat pump is not enough in winter, then you will just heat with electricity, which is not more expensive than having a stove installed.