Cooling with heat pump via underfloor heating?

In Germany, we only have a few hot weeks, so far I have always managed very well without cooling. Now it is almost May and still single-digit temperatures. From September onward, summer is over. In between, as always, many cool and rainy periods.

I also think that natural shading or trees are the better (sufficient) solution than air conditioners.

South-facing windows are well controlled with roof overhangs or building recesses; after all, the sun does us the favor of changing its position with the seasons. A roof can also be designed so that the attic does not become a sauna. West/East with external shading (venetian blinds or those strange deciduous trees). It would be a planning error to ignore such things and design houses where "only" 2-3° heat pump cooling is not sufficient.

This certainly doesn't fit every architecture, but it does for the vast majority of single-family homes.

Greetings from the physicist in the bunker with window area of 40% of the living space 8-)

I also think that natural shading or trees are the better (sufficient) solution than air conditioning.

Sure, they will have grown so big in 10-20 years that the house will also get some shade. Provided there is enough space on the towel-sized plot and the neighbor has nothing against it. Until then, it means sweating or air conditioning.

That certainly doesn’t fit every architecture, but for the vast majority of single-family homes it does.

It’s the other way around. For the vast majority of single-family homes built nowadays, no bigger jumps are possible, especially regarding architecture. One step to the left and one step to the right. Everything else exceeds the budget of the average home builder. Just look at the new housing developments. That any kind of summer heat protection was even thought of can often be seen only in a few houses. What were the most popular and most built houses in Germany in 2020 and 2019 again? Oh yes, Flair 152 and Citylife 143 V. Unfortunately, that’s the reality: off the shelf and with as little variation as possible. This also includes front/rear projections and longer roof overhangs, not to mention external shading. Don’t get me wrong. In a perfect world you could of course do without air conditioners, but for that, the construction method of modern houses would have to be changed, and that comes with costs. In the end, the average builder takes what is simply cheaper overall.

Greetings from the physicist in the bunker with window area of 40% of the living area

Great, that makes you one of the few exceptions (there are supposed to be some... I’ve heard).

I always find the argument "Summer is only 3 months and sometimes it rains" absurd. Summer still comes every year, I don't want to spend a quarter of my life in terrible discomfort just to make that argument, do I? So we are already very curious about the first summer with air conditioning. I spent several weeks of 35-40°C in 2019 heavily pregnant and I never want to experience that again. A comfortable temperature is a piece of quality of life for me. The extra cost for the air conditioning was about 5k for us, which I would have gladly saved somewhere else on the house corners if necessary. But not everyone has to see it that way, I just absolutely don't like it when I'm too hot. Vacation in Crete is nothing for me either. :P

Last year we had a maximum of 24 °C in the bedrooms despite partial south-facing exposure. That is still bearable. In summer we make sure to operate the roller shutters accordingly. Nevertheless, it would be comfortable to have at least some ventilation in the bedrooms.

I always find the argument "Summer is only 3 months and sometimes it rains" absurd. Summer comes every year anyway, I don't want to spend 1/4 of my life in terrible discomfort just to argue that way, do I?
So we are really looking forward to the first summer with air conditioning. In 2019, I spent several weeks of 35-40°C being heavily pregnant and I never want to go through that again. A comfortable temperature is a piece of quality of life for me. The extra cost for the air conditioning was about 5k for us, which I would have gladly saved somewhere else on the house if necessary.
But not everyone has to see it that way, I just really don't like it when I'm too warm. Vacation in Crete is also not for me. :P

1. During the 3 months, it's hot for a maximum of 6 weeks. You can ventilate the rest.
2. Without air conditioning, the house also had a maximum of 26 degrees even when it was 40 outside.
3. Today's youth vote Green, but then install air conditioners so they don't sweat.