Construction costs are currently skyrocketing

At the current prices I hear for photovoltaic, you have to be somewhat in love with the topic anyway, I believe

- Underfloor cooling via geothermal heat exchanger 4k surcharge (1.5 years ago it was still 2k... if only I had fixed that in from the start...). I'm really thinking about whether it's worth it, does anyone know how much effort it is to retrofit later?

It would probably make more sense to put the 4K into a proper air conditioning system...!?

BTT: Earlier, I received a few things for heating and plumbing. - Floor cooling via geothermal heat exchanger 4k surcharge (1.5 years ago it was still 2k... I should have fixed that right away...). I'm really considering whether it's worth it, does anyone know how much effort it is later to retrofit? - Bathroom sampling for 2 shower bathrooms good 9k, shower drains, rimless toilets with soft-close and a washbasin with mirror cabinet upstairs, otherwise no luxury. 9.4k...

If I were you, I would leave out the washbasin with mirror cabinet. It will certainly cost between 3-5k€. Get one yourself, that already saves a lot. For us, the washbasins with a simple countertop and about 1.8m length cost about €3,000... We're now having it made by a cabinet maker and will get it cheaper with a natural stone countertop.

It would probably make more sense to put the 4K into a proper air conditioning system...!?

I definitely won't get that approved by my girlfriend. There are people in this country who convince themselves that air conditioners make you sick...
I'm also not sure if we really need a proper air conditioning system, just because of the altitude and distance from the lake we are then 3-4 degrees below what we currently have, plus the better local climate in the countryside... a floor cooling system for 2k would have been something I'd have said yes to, I'd take that.

If I were you, I would leave out the washbasin with mirror cabinet. That will certainly cost between 3-5 thousand euros. Get one yourself, that will save you a lot. Rimless toilets are included in our price, also soft-close.

2k net. As expected, it is also the most expensive single item. Otherwise, there really isn't much to leave out, somehow everything is expensive.
Instead of specific sanitary equipment, we have a sampling budget, so you simply can't take the standard ;)

I definitely won't get that through with my girlfriend. There are people in this country who convince themselves that air conditioners make you sick...

I actually also "belong to this category" and would never want the unit, for example, in the bedroom. However, if you hang 1-2 devices centrally (e.g. in hallways) and only run them "permanently" at a low level, your girlfriend wouldn’t notice it and would be enthusiastic :)

Besides, theoretically, she would also have to belong to the group that thinks underfloor heating causes thick legs and thrombosis, and in summer ice-cold feet with floor cooling ;)

I'm also not sure if we really need a proper air conditioner, just because of the altitude and distance from the lake we're 3-4 degrees below what we currently have, plus the better local climate in the countryside... in that case, a 2k floor cooling system would have been something I'd say, I'll take that.

Then rather invest a relatively small amount in air conditioning preparation, so that it can be easily retrofitted if needed (too hot after all, or another girlfriend or whatever ;)). You’d probably still stay below 4k with higher efficiency ;)

We do have floor cooling and are quite satisfied with it, but only because it hardly/added no extra cost for us :)

Photovoltaics are useless to you in winter anyway. In January, they don't even reach 20% of the yield they achieve in June/July.

That is not really true ("useless"). Because with a 20KWp system, you generate about 450KWh in January. That is often enough to significantly reduce electricity consumption (halve it or less?). Nevertheless, with the current prices, I wouldn't know how I would decide either. The situation is simply "unfavorable".