Dissatisfied with the new building as there are now other options

The goal itself was already defined 3-4 years ago. Nothing has changed since then.

If you want to hear that your wish is understandable and not madness: here you go, gladly. I don’t want to make excuses for you, nor consider you crazy, and likewise not confirm that it was the courage to a bloody nose ;-) that made you bring up the topic here without a secondary nickname. However, I would recommend not planning a new build right now. A good time, in my opinion, would be when the younger child moves on to secondary school. Then the house is at a very attractive age for house buyers of the "nearly new car" type. Until then, leave it at small things like a nicer kitchen countertop or the like. In your mid-forties, you’ll still be young enough to enjoy the corner windows for a long time, if they are still important to you then. Until then, make a list every year of the desired features for the next house and don’t open the envelope again until you’ve written the next year’s list. Then put both back into the envelope and so on. I’m curious what will remain on the list when we plan the house here in 2026 for moving in 2028. If the new plot allows it, a children’s wing like at could already appear, and/or a "Mutti" extension like with – speaking of panta rei and so on :)

When they are out of toddler/infant age, definitely. It's not that there are no more problems, but this personal dependency of the children and thus the limitation of the parents noticeably decreases. At least that's my experience. That moment did us a lot of good (at the same time the decision was made that the topic is done for us).

You can notice that with us too. The child comes home from school and daycare and disappears outside to the friends. Weekend is similar. The friends ring the doorbell at 10 a.m., and you're lucky if you see the child in between before dinner at 6:30 p.m. In return, sometimes you have 5 or 6 kids there, sneaking from door to door. You no longer have to occupy the child as intensively as in the baby and toddler age. Leisure time as parents increases significantly because of that.

By the way, I think Crossy has the problem that you also have with a new car. The first scratch really hurts and every time you look at it. Others see a beautiful kitchen, only Crossy sees the missing "aircraft carrier." After a few years, a habituation effect sets in.

changes the house with every salary increase until you are in Sanssouci Palace, irony off ;) , you are not Hans in Luck. Make yourselves comfortable in your house and be satisfied until it pinches because it is too small or too big

I'll put it this way: "Easy come, easy go" happens to many when suddenly a lot of money is available. Nothing is good enough anymore, nothing seems impossible anymore. I went through that phase in my early 20s. Even as a single, you can easily get a five-figure income per month without much left over. I had to realize, it doesn't make you happy, it doesn't make you satisfied, quite the opposite. I no longer recognized myself. And now? It means nothing to me anymore. No sporty Mercedes anymore, no, it's a Golf Variant, no brand clothes, nothing. What I want to say is inner contentment is not achieved through the consumption of luxury goods. The thing with your children is really a pity. There's really something to the difference between village and city. My sister was surprised at how things work here. Actively take care of contact. Keep at it. Try to invite the children your children play with. Leave a note with your phone number in the cloakroom of the respective child. I did that too. Even I don't know all the parents around here anymore and yes, Corona doesn't make it easier.

What I can recommend, both for the children and parents, is the volunteer fire department. Our 9-year-old daughter has now been involved for 3 months and is totally enthusiastic...

"Larger windows or corner glazing, fireplace, air conditioning, dining room extended by 1m to rotate the kitchen island and be able to design it like an 'aircraft carrier,' resulting in a different kitchen, possibly a small additional room, KNX instead of FaH, flush doors, and other small details. I do think that in total this would cost 100k.
The most expensive part would of course be the extension. Actually, our house is big enough, but then there would be the possibility to design the kitchen really nicely."

I don't see any ostentation here anywhere. Many others have that too. In my opinion, it is perfectly fine to build the first house a bit more modestly and then, if the financial means allow, to change/expand it again if it is important to you.
My post might not quite fit the topic; I just wanted to counter the "ostentation" a bit.

What does it mean it is not ostentation? Of course it is ostentation or "unnecessary luxury." Nowadays, you can almost call a single-family house ostentation since only a few can afford it now. Then not being satisfied with a house you own because it is not luxurious enough is obviously ostentation. No offense meant, I know it too. Even though we only have a net household income of €6,300, I consider my family rich. I had times as a student when I lived on ready-made spaghetti meals for months because I had no money. With the salary, the wishes/standards also increased. Now, for example, we no longer buy milk from the discount store but from Landliebe, just to give one example.

These are the real problems, not that for average earners building a house is practically no longer possible.

PS: Truly rich people definitely don't hang out in the house building forum. ;)