Floor plan for a single-family house with 200m² with a separate apartment 75 + basement 140m² + garage 56m²

Can I really write it that simply? In my field, I would get it sent back because nothing is specified: At least I would have thought I need to write how big each room should be at minimum, whether with or without a bathtub.

This is heading in the right direction, but it can certainly be more detailed. A list of all rooms on the ground floor and the upper floor works well. Behind the rooms, special requests can be written respectively. For example, for the bedroom: bed is at least 2m wide or wardrobe must be at least 250 x 60cm. Children's room not under 13sqm, etc. Also things like "large window front in the living room or no spiral staircase - list everything. It can take quite a while to get everything together.

If she has a senior handicap, she has to go somewhere else and she knows that. Then hopefully she can live reasonably well from the rent there..

Well, this thread is developing much more positively than the one with the nutcase with the northern pitched roof. Very pleasing!

The quoted statement is a big mistake. If she has a handicap, assisted living is indicated. And the cheapest form of that exceeds any possible rent. You should discuss or get advice about inheritance, gifts, and usufruct or right of residence.

Well, this thread is developing much more positively than the one with the nutcase with the north shed roof. Very pleasing!

Yes, I think so too. Very pleasant conversation with us :)

TK" and the "M".
TK = technology? M= mobility?

TK stands for Technik (technology), T for terrace, M are two inverted V’s and indicate parking spaces.
It was just a sample drawing made for you when you were still planning without a terrace and parallel entrances on the south side.

At least I would have thought I need to write down how big each room should be at minimum,

No. Example: 12 sqm is good as 3 x 4, but can also be poorly executed as 2 x 6.
Furthermore, all rooms should be properly adjusted in proportion to the budget by a specialist. For a 5-person household, for example, the kitchen or the open room will be larger, and rather savings will be made in the bedrooms. For a senior woman, the kitchen will possibly be smaller, and the bedroom larger.
Attention: all this of course because the square meters of the house have to be adapted to the budget. Calculate €3000/sqm, then you should be aware that your number of rooms will be limited and probably the fireplace and sauna will have to wait.

whether with or without bathtub.

Bathtub is included for the architect in the word family ;)

Do you hand over the existing documents from the building authority? The site plan? The answered questions to the building authority? Or do you describe the property as being such and such a size?

Wait for the first meeting. It would be good if you mention the positive building preliminary inquiry on the existing property.

Do the companies know at what height the roof must start, because I can’t find anything.

Does the baker know how to bake rolls?

I would love to build a one- or two-story house, but that apparently isn’t possible. Since the two residential barns (north and east) are not being considered. In the end, only three buildings were taken for comparison and the next large residential building is 3 the other large buildings are not either

If the last sentence ever made sense, moths must have gotten in by now. Lacking a proper aerial photo, I don’t have a clear idea of the situation – but it certainly reads as if the municipality has unduly idiosyncratic ideas about which surroundings should be included in the integration assessment. One might have various legal opinions about that, but the municipality can’t just pick and choose freely either.

Dear Sir or Madam, my mother and I want to build a house together on one plot of land. [...] Sincerely [...] At least I would have thought I need to write down how big each room should be at minimum,

I don’t understand: to which Christchild do you want to send this wishlist anyway? You need an architect, and you don’t acquire one coldly with a letter. One addressed to “Ladies and Gentlemen” would be wrong anyway; for single-family houses, it’s better to approach small offices with only one professional.

Not everyone with a handicap is a case for assisted living or even a nursing home. The gray area is large where the senior, for example, needs help in the morning and otherwise manages reasonably well if the environment is suitable.

And yes, the information provided is sufficient. Especially specifying square meters is nonsense. Your dressing room is huge; the linear meters of the wardrobe can fit in half the space. But if the shoe collection should be included, or a large dresser in the middle as an island, a vanity table, armchair (like you see in movies), then you have to specify it. Square meters alone say nothing about utility and spatial feeling. You have to say what you want. You don't want square meters; you want living comfort. You want certain rooms; you want to accommodate certain things there. Hobby room? Yes, which hobby? Nerdy gaming or painting? Dark or extremely bright without glare?

Dear Sir or Madam,
my mother and I want to build a house together on a plot of land.

I have seen that you are currently active here again – how is your own project going?