Floor plan, living on one level, please provide criticism and suggestions.

Thank you for the explanatory information. Now one can better assess the whole thing.

I assume that residential privacy is particularly important to you since you place cooking and living towards the garden. This means the rooms face north and east. Surely, a north side will have advantages on some days in the height of summer, but if possible, I would prefer the evening sun to the morning sun. Therefore, I would tend to mirror the design – if it should be that one.

With this layout, all bedrooms move not only to the south but also to the street. This is potentially warmer and noisier and may need to be considered architecturally (air conditioning / noise protection).

Your property has a slight slope. With this, you could build a technical room under the ground floor. The ground floor level of the house can be adapted to the terrain in different ways. It projects a bit out of the slope towards the street, but the terrace in the garden is nicely level. An indoor connection is not necessarily needed, and you can simply save yourself the stairwell. This is unusual, but we have also built it that way and have had no disadvantages so far.

Placing the child's room out of earshot of the bedroom is completely fine for an 11-year-old. You could give the child the entire upper floor and make bedroom 1 a study.

Bedroom 1 is not quite clear to me because you are not expecting overnight guests. If it is meant as a room to escape snoring, I would connect it to the dressing hallway. If it is indeed a guest room, I would connect it differently to the bathroom downstairs – or the guest would have to go upstairs to the child’s room – possibly a very undesirable intrusion for an adolescent daughter and possibly a hygiene challenge for the guest in the case of an adolescent son... Just clichés, I know.

The hallway should now work. Guest toilet and laundry room instead of a passage ease the situation.

How does your child get around? Plan the parking space for this mobility. Many of us grew up with the bicycles standing next to the cars in a garage, but that was not ideal. It can be better.

The drawn terrace is good for sitting around, but if it is about also sitting outside with friends at a table, it becomes a bit cramped.

I like the basic concept, with the consistent separation of living functions and the focus on communal rooms. Regarding the design of the gabled roof above the living space / light. Much is not “how it’s done” – the important thing is that you are aware that deviation from the standard costs something: increased square meter price, forgoing maximum everyday efficiency relating to a “normal” everyday life, enduring the headwind of “this is not how it’s done.”

Therefore:

Please once draw proper furniture to scale?

Important—the size and the sensible space around it are often underestimated.

Why should it be built on one level?

I know this question is not directed at me – but I have always loved this and therefore realized it. Does it really need a justification?

Development plan Size of the plot 525m² Slope No Floor area ratio 170m² Floor space index 2 Building window, building line and boundary Edge development 9 meters garage Number of parking spaces 2 Number of floors 2 Roof shape Gable roof Style Modern Orientation see plan Maximum heights/limits see plan

I think the problem is that you do not read or interpret everything as it should be. Floor area ratio (Floor area ratio) is a number starting with a 0, followed by a comma. With a plot of 521 or 525 sqm, I do not get a figure of 170 sqm through cross calculation. Then the floor area ratio is somewhat more complex, since roof overhangs may also be included if applicable. Terrace on the house, which is also approved like Floor space index, meaning a floor space index of 2 would mean that you are allowed to build twice as much living space of 521 sqm. It is self-explanatory that this is probably not the case here in a residential area, since it would be over 1000 sqm allowed. Number of floors of 2 can mean that you must build 2 full floors. The site plan is also too tightly cropped to check whether this or that is correct.

Is a justification really necessary?

If nothing is left of the plot except a 3-meter edge (where one must also note that the garage stands too close to the street), one should find the reason for oneself, yes. The plot is being wasted with the dimensions given here. If you then also use the three meters for a hedge, you actually have nothing left of the plot, not even a view except some greenery at a distance of 2 meters in front of the windows. I find the question quite justified, especially since the way to the child's bathroom, the children's room and the office must also be covered. Then there are also the quite close neighbors who might exploit the potential of the two-storey structure and then be quite close to your own living room. And if you are already planning airspace, then you want to get something from it above as well. Because according to the plan of a bungalow, the air is very thin below. I strongly recommend an architect here who will make the best of the plot and, of course, also take personal wishes into account. Maybe it will be easier for you in a personal conversation to verbally express the “wanting” and “liking” so that you can be helped. Everything else has already been said.

I think the problem is that you don't read or interpret everything the way it is supposed to be. The floor area ratio (Grundflächenzahl) is a number starting with a 0, followed by a comma. For a plot of 521 or 525 sqm, I can't calculate a figure of 170 sqm by cross-multiplying. Then the floor area ratio is somewhat more complex, because roof overhangs may also be included. A terrace attached to the house, which is also approved like the floor space index, so a floor space index of 2 would mean that you are allowed to build twice as much living space as 521 sqm. That this is probably not the case here in a residential area goes without saying, because that would be over 1000 sqm allowed. A building height of 2 can mean that you must build 2 full stories. The site plan is also cut too narrowly to verify whether some things are correct. If nothing remains of the plot except a 3-meter border (although you have to acknowledge that the garage is placed too close to the street), you should find the reason for yourself, yes. The plot is wasted here by the measurements. If you then also use the three meters for a hedge, you essentially have nothing left of the plot, not even a view except some greenery two meters away from the windows. I find the question quite justified, especially since the path to the child's bathroom, the child's room, and the office also has to be covered. Then there are the neighbors nearby, who may take advantage of the potential for two stories and then be quite close to your own living room. And if you plan for an open space above, then you also want to have something of it from above. Because downstairs, according to the bungalow plan, the air will be very thin. I strongly advise you to consult an architect who will get the best out of the plot and, of course, also take personal wishes into account. Maybe it will be easier for you in a personal conversation to verbally express the “want” and “like” so that you can be helped. Everything else has already been said.

Attached is the floor plan, which is specified as 170 m², was also included in the image, and the size also includes the canopy.

Okay. Some things are clearer to me.

Then let's get started:

1. Costs:
700,000 will probably be tight, in my opinion.
Quick estimate:
The most comparable is a bungalow; turnkey construction prices start at about €4,000.
If I calculate about €4,000 for the basement and "only" €2,000 for the upper floor (since it normalizes with the upper floor), I already get about €700,000. For the concept to work, the double garage must also be included (almost impossible to stay under €50,000 here) as well as the terrace paving (since it's almost integrated into the house) at least another €10,000 => €760,000 without ancillary construction costs. For a slope, I simply assume 20% ancillary construction costs now => I expect more like €910,000 here.
(Special wishes like clinker facade, smart home, etc. would be extra. If you go somewhat below today's standard, e.g., cheap floor coverings, textured wallpaper, and so on, you should still be able to get just under €875,000.)
(My figures above are, in my view, conservatively calculated. Last year my better half was whispered crazy ideas about a bungalow by the in-laws, and there were no turnkey offers for €4,000, rather a bit more. The high air space also makes it more expensive than a normal bungalow.)

2. I know, this will be tough. And I'm not writing this to create bad vibes but to warn about later problems.
From my point of view, the plot is not suitable for the planned house. The plot is too small for this.
Then there is the slope, which also makes it more expensive (the more ground area a house needs, the more expensive the slope gets).
Even though this is entirely against your wish, I would not try to implement a "living on one level" concept here, unless there are health reasons for it.
And if there are health reasons, I would start thinking more innovatively: Okay, open plan room, main bathroom, and one bedroom downstairs. Second bedroom (guest room? snore-escape room? No overnight guests are indicated) upstairs. Laundry room upstairs.
Alternatively, take advantage of the slope and put technology, laundry room, office, etc. downstairs. Rethink the whole thing to significantly reduce the exterior dimensions of the house.
Here only a little edge remains of the plot and a grass area barely larger than the garage.

Here again applies: if you are aware of this and it is allowed, okay.

3. But: I fear it is not allowed.
The floor area ratio (Grundflächenzahl) normally indicates how much may be built over (what counts depends on the age of the development plan). This is normally a 0,x number and is multiplied by the size of the plot. (Example: Floor area ratio 0.5 and plot 500 m² = 250 m² buildable area, plot 600 m² = 300 m² buildable area)
There it says 170 m², which is very unusual.
But okay. Some municipalities are like that.
If it is a fairly new development plan, it means: a maximum of 170 m² may be built on. Terrace and garage count toward this, depending on the statute only partially (in the sense that the terrace area may exceed the floor area ratio by a certain percentage). I roughly calculate about 300 m² built-up area. Even if I miscalculated (which is possible, not all dimensions were given), this is significantly more than 260 m².
The main building alone consumes the floor area ratio. With ancillary buildings, depending on the exact age of the development plan, it may be exceeded. In the best case by 50% => 255 m² would then be the limit. However, this is not certain either - there are also development plans which do not allow this excess.
If it is an old development plan, this can be different here; then, for example, terraces and driveways might not count (depending on age).
In newer development plans, permeable ground (which then only applies to driveways and the like) is counted less.
If not: big problem.
This needs urgent clarification. I assume the plan will currently not be approved because too much area is built over.

Next steps: Clarify from what year the development plan is.
Clarify what counts toward the floor area ratio and with which factor it is accounted for, and what options there are to design areas differently (e.g. in some new development plans: permeable driveway -> only 50% accounting).

3. Placement of windows and placement of rooms also offer some optimization possibilities, as others have already written.
My brain refuses to think about the floor plan right now because I fear that the floor area ratio will be exceeded anyway.

I think it is clear to everyone that the house will not be built exactly as it is drawn. The basic idea is clear and can basically be realized on the property in a somewhat different form. If the garage and the utility room including the technology are moved under the house, it will not be so tight with the property anymore and the floor area ratio can be maintained. I see the €700,000 as a wish budget. It is unclear how much elasticity is still possible to fulfill the wishes. Not everyone approaches the pain threshold with their wish budget. By the way, I also think that with the wish budget, about 2/3 of the construction project can be realized if you calculate full costs from the first groundbreaking to the last terrace paving stone.

When I presented my construction project as Hampshire about years ago, you were also quite nice to me and thought along. Building a bungalow with a gable roof and a "void" on a slope – that works, we did it and it is great to live in. Only one thing does not work with that: optimizing construction costs per square meter. In the end, we did not implement all ideas but the essential ones. But I did not understand the requirement from as if that is the goal here.

I consider the advice to go to an architect absolutely sensible.

Okay. Some things are becoming clearer to me.

Then let's go:

1. Costs:
700,000 will likely be barely enough, in my opinion.
Quick estimation:
The most comparable is a bungalow, where turnkey construction prices start at about €4,000 per square meter.
If I calculate about 4000 for the basement and only 2000 for the upper floor (since it balances out with the upper floor), I already come to about €700,000 just for that. For the concept to work, the double garage still has to be included (almost impossible to stay under €50,000 there) as well as the terrace paving (which is basically integrated into the house) with at least another €10,000 => €760,000 without incidental construction costs. With the slope, I simply assume 20% incidental costs => I rather estimate around €910,000 here.
(Special requests like clinker facade, smart home, and so on would add on top. If you step down a bit from today's standard, e.g., cheaper floor coverings, textured wallpaper, etc., you should still be able to get just under €875,000.)
(My numbers above are, in my view, cautiously calculated. My better half was fed some ideas about bungalows by her parents-in-law last year, and there were no turnkey offers at €4,000, more like a bit above. The high air space also makes it more expensive than a normal bungalow.)

2. I know this will be harsh now. And I’m not writing this to create bad vibes but to warn about potential problems later on.
From my perspective, the plot is not suitable for the planned house. The plot is too small for that.
Then there's the slope that also makes it more expensive (the more floor space a house needs, the more expensive the slope becomes).
Even if this goes completely against the wish, I would not try to implement a "single-level living" concept here, unless there are health reasons for it.
And if there are health reasons, I would start thinking more innovatively: Okay, open space, main bathroom and one bedroom downstairs. Second bedroom (guest room? Snoring escape room? Zero overnight guests have been indicated) upstairs. Laundry room upstairs.
Alternatively, take advantage of the slope and put technology, laundry room, office, etc. downstairs. Rethink the whole thing to significantly reduce the external dimensions of the house.
This leaves only a little edge of the plot and a grass area, barely larger than the garage.

The point is: If you are aware of this and it's permitted, okay.

3. But: I fear it is not allowed.
The floor area ratio usually indicates how much may be built over (what counts depends on the age of the development plan). Normally it is a 0.x number and is multiplied by the size of the plot. (Example: floor area ratio 0.5 and plot 500 m² = 250 m² buildable area, plot 600 m² = 300 m² buildable area)
It says 170 m² here, which is super unusual.
But okay. Some municipalities are like that.
If it is a fairly new development plan, it means: maximum 170 m² may be built. Terrace and garage count towards this, depending on the statute only partially (meaning the terrace area may exceed the floor area ratio by a certain percentage). I roughly come to about 300 m² built-up area. Even if I miscalculated (possible, not all dimensions given), that is clearly more than 260 m².
The main building alone consumes the floor area allowance. With auxiliary facilities, depending on the exact age of the development plan, an excess may be allowed. Optimally up to 50% => then the limit would be 255 m². But this is not certain either – there are also development plans that do not allow this excess in that way.
If it is an old development plan, it may be different here; then terrace and driveway probably wouldn’t count (depending on age).
In newer development plans, permeable ground (which only applies to driveway and such) may be counted lower.
If not: big problem.
This urgently needs clarification. I assume that the plan currently will not be approved because too much area is being built up.

Next steps: Determine the year the development plan comes from.
Clarify what counts toward the floor area ratio and with what factor, and what possibilities there are to design areas differently (e.g., in some new development plans: permeable driveway -> only 50% counting).

3. Placement of windows and rooms also offers certain optimization options, as others have already written.
My brain is refusing to think about the floor plan right now because I fear the floor area ratio will be exceeded anyway.

With

I think it’s clear to everyone that the house will not be built exactly as it is drawn.
The basic idea is clear and will basically be realizable on the plot in a somewhat different form.
If the garage and house connection room plus technology are moved under the house, it will no longer be so tight with the plot and the floor area ratio can be met.
I see the €700,000 as a wish budget. It is unclear how much flexibility is still in there to fulfill the wishes. Not everyone pushes their wish budget to the limit. By the way, I also think you can realize about 2/3 of the building project with the wish budget if you count full costs from the first spade to the last terrace paving stone.

When I presented my building project about years ago as Hampshire, you were quite nice to me, you thought along. Putting a bungalow with a pitched roof and “air space” on a slope - that works, we did it and life in it is great. Only one thing doesn’t work: optimizing construction costs per square meter. In the end, we didn’t implement all ideas but the essential ones. But I didn’t understand ’s requirement as aiming for that here.

I consider going to an architect as absolutely sensible advice.

I share your opinion on the budget: It’s not sensible to compare one with the other, and that is not my intention either.