One has to be able to imagine your life situation in order to think along. Usually, this is the young family with x children, and there are similar needs and also the desire to reduce costs, and a discussion arises.
You would also experience lively participation, but for that, one has to know considerably more about your personal background and intentions.
A house for you alone and mother in an [Einliegerwohnung] with 315 sqm makes no sense without further context. Afterwards, one reads about x "guests," but it is a difference whether this perhaps means your own children aged x+y, for whom you might want to create situation Z, or if you have a certain hobby, etc. Without such detailed knowledge, participation does not work, and of course, people here try to question the high demand for expensive living space because in 100% of cases it is also about limiting the cost of a house.
For that, a personal contribution must also be defined.
later the option for a holiday apartment
The [Einliegerwohnung] or your apartment or both after an intended (already pre-planned now) renovation?
With the general contractors, we ended up at 580K for the entire house, so a part of the house for 700k is probably quite possible.
Of course, the statement that 580k should be enough for a 315 sqm "complete" house is unrealistic. That will be told to you as well. You would have to describe that in more detail so that it can be understood. Nobody wants to know your private life, but you have to know these things to be able to think along.
I am planning a house for up to 7 people......
Suddenly seven, that came only later, and here it is also important which people are involved and what needs arise from that. Are these people always present? Children? Visitors? etc.
where another architect rejected it in a preliminary talk.
...what was the reason given by the architect?
The guest room is for guests, not for old age. If that were the case, it would probably be called an old-age room.
Not least for cost reasons, one at least looks for the possibility of multiple use of a room.
A friendly answer is something different; in my opinion, you felt offended without reason.
When I grow old and gray, I would move into the [Einliegerwohnung], just like with the bathroom. It is only for the first two years and then at most for guests, but I understand that an open bathroom directly in the living room would naturally be better for you?!?
And how should anyone know that if you had not said it before? You complain that people here do not already know your thoughts beforehand.
Yes, exactly, the goal was to design everything modularly.
Modular is an elastic term or apparently you do not define it in a generally valid or understandable way. By the term, one would expect a coordinated modular system for a certain type of use, which one cannot recognize here. The rooms are neither designed nor concretely furnished, so nothing modular about that. Just because you want to install a partition wall later does not make it modular construction.
Uh, okay, maybe you understand “parts” differently than I do, but the layout jumps right at you. Depending on the layout, only short drywall partitions with doors have to be built there.
Even there, doors alone are not enough; otherwise, you will have trapped rooms later. Likewise, windows must fit, access routes, electricity. Of course, much can be done, but in order to be able to redesign it later if needed, one must consider these scenarios and maybe even prepare things in advance. But for that, you have to also specify the possible scenario.
That is why I do not want to build the whole house but modularly.
As already described, you would have to describe this desire for modularity once if someone here is to participate or explain what modular function currently consists of.
I also do not want to rent out anything but still think about the future.
Earlier, I read very well about renting as a holiday apartment; when is that planned, for fun or to fill a tight budget? What does your "thinking about the future" include? If I want to cushion something structurally or otherwise in life, I have to know what I want to achieve and build in advance exactly for that. Simply big or a lot is not helpful.
but the house can already depict one or two scenarios
Yes, which ones...? There are thousands, and understandably everyone means something different by that.
Unfortunately, I had assumed that someone would still tell me what I absolutely have to improve and not a discussion about possible building regulations or family planning.
One could only "improve" something if one receives the necessary context from you, i.e., knows the background and intentions of your project.
From the multiple identical feedbacks and the fact that floor plans and building projects have been constructively discussed here for years, you should perhaps consider responding precisely to individual inquiries and not react stubbornly as if you were being attacked; nobody here is doing that.
Try it once; you can lose nothing by doing so; there is much knowledge and experience to gain from participating experienced builders and involved professionals. Just assume that people here want to help you, and everyone here, just like you, carries their own package around.