Construction costs are currently skyrocketing

If you want it efficient (and have the space), you try to maximize the string length. Rule of thumb: 20 modules with the same orientation in one string. The more, the less the influence of shading. Possibly a second one parallel to it (often more is not possible due to the current). Next string. In very small systems with fewer than eight modules of the same orientation, you may have to approach it differently. But that goes too much into detail. The bypass diodes have long been standard. You don’t have to pay attention to anything there. What I still don’t understand is why you need "3 x something" cables for photovoltaics. From the modules to the inverter, you need two DC lines of the appropriate cross-section per string and one thick ground wire for the entire system. You only need 3 x something behind the inverter, which ideally is not too far from the fuse box, so it does not require many meters of cable duct.

It's gotten pretty off-topic now.

What does it look like concretely for those who are currently getting quotes? Is the extreme trend overall continuing like this?

It looks like that for now. We have just received revised quotes for natural stone slabs and window handles. The slabs are 12% more expensive compared to the 2020 quote and the window handles 11.5%. For the tiles from Villeroy & Boch, an as yet not exactly known increase has been indicated. Nothing that surprises us.

Preparing photovoltaics is basically OK. However, you should mentally prepare for the fact that it will still need to be carried out at short notice (possibly already during construction). I firmly believe that the new government will take some action on this (ideally a mix of carrot and stick, and then you should take a look at the carrot).

You really should reconsider the "plan" to initially install gas and later convert to a heat pump. You now have to pay for the gas connection and chimney, which you actually don’t need at all. And what should give you confidence in heat pumps? These things have been around for decades and are already standing around at your place, e.g. disguised as a refrigerator.

So building a house without a chimney is completely pointless. Every house should have at least one, if not more chimneys. Because retrofitting them later involves a considerably greater effort, possibly no longer feasible. Times are changing.

A nice kitchen stove with a cooking surface, viewing window, and integrated oven, of course heatable with wood and coal, equipped as a continuous-fire stove. That is quality of living for me. I don’t want to miss it, just like the fireplace in the living room. The chimney runs through the middle of the house and completely heats it through in winter. And I really don’t care about my CO² footprint. The tree that emits CO² at night doesn’t really think about it either.

In any case, I would not rely solely on a heat pump as the primary and only heat source. We don’t know how electricity prices and inflationary tendencies will develop. I also don’t feel like chasing the cheapest heating system every few years. I don’t like underfloor heating either. It is, first of all, very slow, unhealthy, and you simply cannot generate localized heat. In winter, when I come in frozen, I sometimes have 25 degrees in the kitchen. On the other hand, I also don’t like the always-warm feet caused by underfloor heating. In the bathroom, yes gladly. But not more than that.

Prices for solar systems will continue to rise sharply according to demand. Of course, there are other points. If the minimum wage is raised to 12 euros, the entire salary structure will also increase. This will also affect the calculated calculations. That material costs and labor wages will decrease, i.e. construction costs in general, I currently do not see.

Should you present your argument to the FDP: No minimum wage - otherwise all houses would have to be equipped with a fireplace. You’d even get the Greens on board with that, they definitely don’t want that... :p If you could eat nonsense with sauce, I would owe you a tab now.

Are there actually already such small single-family private nuclear power plants? I trust myself to operate it, I have understood the principle, and I sell the waste to the hospital for their radiation therapy department.

Are there actually already such small single-family home private nuclear power plants? I think I can handle the operation, I understand the principle, and I sell the waste to the hospital for their radiation department.

For a long time now: Christmas at the Hoppenstedts :D