... and the construction companies all no longer give any useful hints for improvement...
What, what? Why is that? What did they say or not say? Who is supposed to create the plan?
Slope: Yes - 5m height difference over 40m property length, slope from the street (north) towards the south
Oh dear, and they are leaving you to deal with that alone? Even some experienced planners have a hard time with slopes. Trying to solve something here as a layperson will be nonsense in my opinion. Thinking that the basement will save you from all the inclines of the landscape is a misconception. Besides that, there's the financial question and the question of garden design. I'll just ask cheerfully: What will you build your terrace on? Is it floating in the air? Or do you really want to pile up these masses of material against the slope to bring this galactic terrace to the living room? How should the slope from the terrace into the garden be designed? You have about 1m height difference over 8m. Plus 5m distance to the street – the parking spaces would have to be partly basemented if you don’t want a sloped driveway. Your neighbor on the plan’s left side has already done this, if the cutout is correct. How did he solve it? I would just ring the bell and invite myself for coffee. A great test to see what you like and what you don’t. Where is his terrace? How is the garden connection? Did he level the property within the building field or also basement it?
Maximum heights/limits: 9m
From where? Street?
Number of people, ages: 39 years, 45 years, 4 years, 0 years Room requirements on ground and upper floor: * Ground floor: large room for living, dining, and cooking, plus study and shower bath * Upper floor: 3 children’s rooms, 1 master bedroom, large family bathroom ... Overnight guests per year: 12x per year
What is intended for whom here? Why 3 children’s rooms – I only count 2 children. Is the office also meant to be a guest room? I don’t see a guest room in the basement. But there is an unnecessary light shaft to illuminate of all things the slope-side room. That is like putting the cart before the horse. Or did I misread:
Slope from street (north) to south
So the street is at the top and the house below, right?
Price estimate according to architect/planner: €650,000 Personal price limit for the house, incl. equipment: €700,000
That will be the crunch point. The 650K are presumably only the house with a standard basement from the manufacturer. But you are on a slope and want to use the basement also as a hobby room etc. Plus the costs for outdoor landscaping, which will probably shock you. Terrace, paths, stairs, and retaining walls – they will consume a considerable chunk of money. That brings you to the next question – how do you use and organize the rooms in the basement sensibly? Can you really afford to build 50 sqm of storage space that otherwise doesn’t serve a specific purpose? Which hobby deserves its own room of that size? What are these retaining walls actually supposed to support? Especially the wall on the south side makes no real sense in my opinion. I don’t want to say anything about the floor plan itself yet – it’s worthless as long as you haven’t fully integrated the plan into the slope. Show the exterior views including slope, paths, terrace + retaining walls.