Dissatisfied with the new building as there are now other options

In total, we are talking about approximately 4k more per month.

You are 36 and 37 with children aged 4 and 6. Being able to live your family life a relaxed 4k below the "how much longer can we afford the house" stress level is enviable luck, and the downside of a kitchen that could have one more star is bearable ;-) What was the final status of – and (where) is the result posted in the house pictures thread?

You can also buy nice second homes. :)

[LARGE windows or corner glazing, fireplace, air conditioning, dining room extended by 1m to rotate the kitchen island and be able to design it as an "aircraft carrier," resulting in a different kitchen, possibly a small additional room, KNX instead of FaH, flush doors, and other small stuff. I do think that altogether it would cost 100k.
The most expensive part would of course be the enlargement. Actually, our house is big enough, but then there would be the possibility to design the kitchen really nicely.
Windows can’t just be changed anymore (I find that the worst). Fireplace only works with such an exterior chimney and the position is then not ideal.

Yes, it is 4k net more. Our monthly income is now five digits and was already okay before. Also, we both don’t work full time (70 & 80%), but not in Germany.]

Larger windows or corner glazing
That is primarily just aesthetics at first, or are the rooms too dark?

Fireplace
Retrofit possible, possibly with compromises on positioning. With coin-operated also conceivable inside, but requires appropriate breakthroughs.

Air conditioning
Also retrofit possible. I’ve learned that air conditioning companies can find very interesting means and ways there.

Dining room extended by 1m to rotate the kitchen island and be able to design it as an "aircraft carrier,"
resulting in a different kitchen, possibly a small additional room
Would the addition of a heated winter garden be conceivable?

[LINK=https://www.hausbau-forum.de/threads/knx-erfahrungen-installation-in-einfamilienhaus.32644/]KNX[/LINK]
That would indeed be extensive now without a major renovation if it is to be done comprehensively. But maybe there is a particular pain point so that one could think about a targeted solution?

Flush doors
Definitely retrofit possible.

Let loose in the garden, you can really sink a lot of money there and upgrade the property. High-quality wooden decking, you can also easily spend five figures on terrace furniture (there are really cool things ...), what about a large sun sail, maybe a hot tub underneath? Pool generally a topic?
Inside you can also do a lot. Art, sculptures. Maybe you only have the CPL countertop in the kitchen now and exchange it for something more high-quality?
Buy cars if you like that. Upgrades for vacations, maybe a holiday home? Did you ever want to have your own horse?

There really is so much luxury stuff. Enough has been invested in the living situation for now. There are also other nice things, even if that might be hard to consider after years of house building. Projects are everywhere ...]

Mh..I think your problem is hard to assess if you don't know you personally, because then you can't really grasp the root of this dissatisfaction from the outside. Did you really have to restrict yourselves too much here and actually your house doesn't suit you and your wishes? Or is there something completely different behind this dissatisfaction, which doesn't have much to do with the house or the windows themselves (e.g. that one has always had to restrict oneself and finally wants to enjoy and also show successes, just as an example)? I think if I were you, I would start there and ask myself very ruthlessly whether a new house that fulfills all wishes really makes me happier or whether it is this very human "there could still be something better" which others also apply to partners, jobs or their appearance and are often unhappier than before and only then realize that good was actually good enough. My parents were in the same situation as you, my dad made a sensational career fairly unexpectedly after buying the house and could have quickly fulfilled his dream of a Bauhaus villa with a view over a valley but realized that my mom was right in her opinion that our terraced house with a large garden was perfect for us. We had great neighbors with many children, a super nice floor plan, a lovingly furnished and cozy house and a quiet residential area at a good distance from my dad’s work. Unfortunately, my dad suddenly passed away two years ago which has led to my husband and me being able to implement basically every house-building gadget through inheritance if we wanted to, but we simply don’t do it for many things like KNX, wood-aluminum windows or beaver tail tiles because it’s not worth the money to us and because through my history I know that the family inside the house is the most important thing and the happiness it brings can’t be replaced by anything. That of course doesn’t mean that we haven’t fulfilled one or the other dream and I can well understand if you are a little annoyed in hindsight, especially about things that are hard to change. With my own life experience, I would therefore probably still give you the advice to consider whether good really isn’t good enough, because you often focus too much on what you don’t have instead of being grateful for the really beautiful and important things you already have, which won’t be there forever like health, your own family, an intact and quiet neighborhood, the feeling of having arrived, etc. If your house suits you more or less: Enjoy it for the next years, make it even more yours and treat yourselves here and there to other luxuries that bring you joy (debt-free earlier, great trips, a pool, a stylish outdoor kitchen, an extension with big panoramic windows?:) and spare yourselves the nerve-wracking time of searching for a new plot, a second house build and all the stress that comes with it alongside children:)

Sounds very much like perfectionism.........I say that too, because I know it from myself :D I was also repeatedly bothered by many things, partly small details....sometimes self-inflicted, sometimes due to poor advice. Everyone here has their own opinion on this, but my advice: look at it positively, new beautiful house, plus a financially great location. You will (probably) not be completely happy again after all the renovations or a new build. There’s always room for improvement....watch TV once and you already think, well, here and there could be a bit more. How about this thought: The house is now perfect with kids, garden, space, etc....later in old age it will eventually be too much work with the garden, cleaning, etc....then maybe a nice penthouse apartment in a great location would be something. That can also last well into old age...all on one level, wheelchair accessible. Depending on the situation, that is the deciding factor in older age whether it’s still possible to live at home or not. And even if only one of you should need care or is rather looked after by the other. It then makes a difference whether you have to constantly go up and down the stairs for everything, etc. You could cleverly have your money work for you now and when the kids are out or something, you could take on a new property again to some extent.

You are 36 and 37 with children aged 4 and 6. Being able to lead your family life 4k below the "how long can we still afford the place" stress level is enviable luck, and the downside of a "couldhaveonemorestarredkitchen" is manageable ;-) What was the final status regarding - and (where) is the result posted in the house pictures thread?

Well researched. I imagine I am still anonymous here at the moment and therefore there will be no pictures. The floor plans shown in the linked thread were each initial drafts from different GCs. Our house is roughly based on post 15.