Floor plan house with granny flat - improvement suggestions?

Nevertheless, I see a clear advisory responsibility,

No. There is no consultation at a construction company. That is exactly the difference.
How do you think the consultation should look like? "Lower your demands," "take a bigger plot," "question the granny flat," "take a bigger loan"?
If you need a plus-size wedding dress and only have a normal budget, you don’t buy at a specialist retailer, you might have to advise yourself or rely on your best friend and maybe live with the "small" shortcomings. Bad example, you take the dress off again. Still, you will see the photos even in 30 years from the "most beautiful day in life."

You are of course right, those who buy cheap often buy often.

Building a house with [BU] does not necessarily have to be cheap. The focus is just a bit different. Turnkey, after all.

when the planner starts to draw in children's furniture (reminds me of the dwarf tables often seen in doctors’ offices).

Then have a look at #65, the [BU]'s planning, I assume. I don’t see any doll furniture there. And yes, as says: you get what is demanded. Somehow you have to yield to the plot.

Will you tell me the post number where I supposedly overlooked the "cuddling"?

Sure: #123

Unfortunately, I fear that there could be problems with the construction company if we make major changes to the plan. I spoke with the construction company today and informed them that we want to change the plan a bit. They were of course anything but thrilled about this idea and told me that with major changes the construction project would be further delayed and we might also lose the price guarantee. Small changes to the floor plan should not be a problem, though.
Since we have a meeting with the construction company next week, I wanted to hear your advice again about how the current floor plan can be changed most sensibly?

No. There is no consulting at a construction company. That is exactly what makes the difference.

Yes, of course. Every seller is a consultant. I also can’t sell my customers a plant that immediately gets eaten by their favorite animal. That just doesn’t work. My employees are not allowed to do that either. The customers then rightly complain.

What do you think consulting should look like? "Scale down your wishes," "choose a bigger plot," "question the granny flat," "take a bigger loan"?

Yes, for example. We managed to get the original poster to stop building within 2 days in a forum. What could the construction company have prevented beforehand, I wonder?

Then take a look at #65, the construction company’s plan, I assume. I don’t see any doll furniture there. And yes, as says: what comes out is exactly what is demanded. Somehow you have to adapt to the plot.

I see a doll table of 60cm (?) in the granny flat kitchen for 3 people. What do you call that? I call that doll furniture.

Anyway, it is certainly difficult to find the person responsible. We were not there and don’t know what has already happened. The original poster does not appear to be particularly communicative either. But you also always have to see that a whole (working) life depends on it and you have to be above that as a professional.

Yes, for example. We managed in a forum within 2 days to get the OP to stop the construction.

Great. Now we can pat ourselves on the back. I don’t find that so great... but I also have a communication problem with the OP... so in those few days other "improvements" could have been proposed here that the builder would still have accepted.

What wouldn’t the builder have already achieved in advance, I ask myself?

Sorry, that’s not his role at all, to put himself in our role?! He has to satisfy the client. And it would have been Carmen-Marlene’s role to review the draft. I already said it: the thread back then was ended by her!

I see a doll table of 60cm (?) in the granny flat kitchen for 3 people. What do you call that? I call that doll furniture.

Yeah... haha... 60 is really extreme. But 80 would work for two. And if visitors come, the crank on the coffee table just has to be operated ;) No, seriously: you also have to differentiate a granny flat for seniors from a family apartment for 3 people. It’s more about functionality and a more settled, quieter lifestyle than about 3-course meals and a house for friends. Even a good planner can’t squeeze a square peg into a round hole.

Great. Now we can pat ourselves on the back. I don't find that so great... but I also have a communication problem with the OP... so that the few days here could also have brought other "improvements" that the BU would still have accepted. Sorry, that's not his role at all, to put himself in our shoes?! He has to satisfy the client. And it would have been Carmen-Marlene's role to review the draft. I already said: the thread back then was aborted by her!

I just wanted to make clear that the OP does see problems if you point them out to her. The BU could have managed that accordingly as well. That she accepts these due to lack of space and budget is another question. I recall a comment that the OP bought the plot on the BU's recommendation. How can he recommend that under these circumstances, I wonder?

Even a good planner simply can't force a square peg into a triangular hole.

In the end, 90% of builders want a castle, although they can only afford a standard hut. A good planner informs the builders and also rejects projects if they simply won't fit. But apparently we see that quite differently, which is also okay.

Of course: #123

They act bitchy there, yes - but who is backing down because of that?

They are acting bitchy, yes - but who is cowering because of that now?

The OP, who else? Instead of re-planning, she wants to make the botched job worse. Well, we'll see. Maybe it will work with the brother being kicked out.