Floor plan of our bungalow

Connection costs have already been requested in detail from the utility providers and taken into account (also with regard to the approx. 42m to the house).

The partial service of an architect to check the trades and obtain offers is based on the suggestion of an architect. Maybe I was unclear.
The scheduling, which I cannot manage, will be taken over by the shell construction company (probably the financial profit will no longer be quite as high, this will be discussed with the company, but first we need a floor plan).

Is there anything else I need to know before I start drawing?

Very kind of you
The house in relation to the property must be taken into account.

- on the one hand, it must not be closer to the eastern boundary than 5m, so that a turning maneuver with the car is possible
- the distance from the house to the south-western boundary should not be less than 12m, every meter counts (the course of this boundary is angled and it was previously planned to consider the "left part" of the garden as the main living area, as the space there is most generous)
- the living room/kitchen/dining area should be at least 60sqm
- otherwise, the bathroom and utility room should not be smaller
- bedroom acoustically decoupled from the hallway, bathroom, child’s room and living room (no problem if the way to the bathroom leads through the hallway and dressing room)

Thank you very much in advance!

- the living room/kitchen/dining area should be at least 60sqm

Sorry, but that's nonsense. That's exactly how I approached the matter in the beginning. Min. 60, preferably 65sqm. It's not the square meters that decide the usability and the feeling of a room, but the usability of the space.

Our cooking/dining area is 31sqm, the living room 22sqm and is more easily furnished than some 60 or 65sqm hall.

And that’s exactly how your living room seems to me.

The couch may be a maximum of ~3.05m wide so that it does not protrude. How big is your desired couch? The kitchen island (work island) is how big 1.50x0.90? That’s certainly sufficient, but not really generous. How big is the dining table? Plotted advance of 1.70x0.80? Seems very small to me.

On the other hand, the 2 seats in front of the fireplace seem like fillers to me, or do you really use them like in a classic fireplace room?

Our cooking/dining area is 31m², the living room 22m² and is easier to furnish than some 60 or 65m² hall.

You are probably right, a minimum size of 60sqm is probably exaggerated. 50sqm are certainly enough.
However, I like large living rooms that still feel cozy with "warm colors" (wooden furniture, possibly wooden floors (tiles in wood look)). Even if they are no longer small and cozy.

The couch may be at most ~3.05m wide

Well estimated
3.15m are the dimensions of our current couch and we wouldn’t want a bigger one

How big is the kitchen island (work island), 1.50x90?

160x90

How big is the dining table? Marked lead with 1.70x0.80?

180x100 the table will be a version with extensions on both sides so that it can be extended towards the fireplace for family gatherings
- here it was also positive that there is a lot of space towards the fireplace because family gatherings are sometimes quite large with us

On the other hand, the 2 seats in front of the fireplace seem like fillers, or do you really use them like in a classic fireplace room?

If the seats are not used in summer, it seems decorative to us and when guests come, the light recliners can be pulled to the TV table.
In winter, a reading corner.

Thank you also for your drawing, but when I apply it in proportion to the property, we hardly have any garden left towards the terrace.

Unlike the many large houses and living rooms here in the forum, we have our living-dining area at about 30m² quite small. Despite the comparatively small size, the room initially sounded like a train station hall due to the wood-look tiles. Through large canvas pictures and plants and decorations, we have somewhat reduced the echo, but I don’t want to know how that would feel in a 60m² room.

Definitely a good tip, however we have seen 2 show houses where the living/dining/kitchen area was about 70sqm and still had no noticeable echo. Probably depends on the furnishing??! In every possible corner of our place there will be large houseplants... for everything that doesn't have flowers we have a green thumb (or rather Seramis)