Single-family house ~180m² in the city with a view of a nature reserve

Hello dear forum members,

after having the great fortune of being allowed to build on a beautiful family property near the city and yet in the countryside, with a view of the nature reserve, my girlfriend and I are in the middle of planning our single-family house.
The start of construction is planned for spring 2022, the offer survey in the 2nd and 3rd quarter of 2021.

We would be very grateful for any tips and opinions on the attached designs. Many thanks in advance.

(The dimensioning of the attached plans may not be optimal, please forgive that.)

Development plan/restrictions:
Plot size: 850 m²
Slope: No (slightly sloping terrain, not yet precisely measured)
Site coverage ratio: No development plan
Floor area ratio: No development plan
Building window, building line and boundary: No development plan (--> according to the Bavarian State Building Code)
Edge development: Double garage planned with 6 x 9 m
Number of parking spaces: 2 vehicle parking spaces in front of the garage + 2 vehicle parking spaces in the garage
Number of floors: 2 full floors
Roof type: Flat roof
Style: Modern (inspired by Bauhaus style)
Orientation: North-South with entrance in the north and window front in the south
Maximum heights/limits: No development plan (neighbor buildings east: 3 full floors / west: 2 1/2 full floors)

Requirements of the builders
Style, roof type, building type: Modern single-family house in the city with flat roof in Bauhaus style
Basement, floors: 2 full floors, without basement (--> cost savings)
Number of persons, age: 2 persons (33 + 32) + 1-2 children (in progress)
Space requirement on ground and upper floors: ~180 m² over both floors
Office: Combination of office (20-40% home office), guest room and parents' bedroom for old age on the ground floor
Guests per year: approx. 10-12
Open or closed architecture: Middle way
Conservative or modern construction: modern
Open kitchen, cooking island: Open kitchen to dining area with counter
Number of dining seats: 6-8
Fireplace: No
Music/stereo wall: Yes
Balcony, roof terrace: No (--> cost savings)
Garage, carport: Solid garage (optional: prefabricated garage)

House design
Designer: Own planning with Sweet Home 3D based on forum information and discussions with other builders

What do you particularly like? Why?
- Entrance area with view through the window front in the living room into the garden
- complete south orientation of all living/sleeping rooms with many windows and view of the nature reserve
- ground floor completely age-appropriate designed
- direct access between garage and house
- fixed roof covering of the outdoor seating area on the ground floor through the offset upper floor (thus no awning etc. necessary that has to be attached separately)
- all rooms with water connection or technical room located on the north side (short pipe routes)
- open living/dining area including kitchen in L-shape (no direct line of sight between kitchen and living room)
- separate parents’ wing on the upper floor with own bathroom, dressing area separated from sleeping area by wall/optical separation
- use of the area under the stairs half for technical room and half for pantry possible
- separate laundry area with washing machine, dryer, laundry baskets (visual separation) on the upper floor/children's bathroom
- small wardrobe on the ground floor can be removed to move the washing machine from the upper floor there if necessary (water connection provided for this)
- the wall between the two children's rooms will only be inserted later, so initially there is a large room of approx. 31 m² (for one child)

What do you not like? Why?
- currently the living area is still somewhat above the planned 180 m² (which is bad in view of the cost calculation)

Price estimate according to own calculation: 400,000 € house (with windows + bathrooms + floor coverings + electrical), 40,000 € garage, 30,000 € kitchen, 20,000 € outdoor facilities (minimal effort (lawn) with expansion in the coming decades), 20,000 € incidental costs (development, notary, soil report, lawyer, etc.)
Personal price limit for the house, including equipment: 550,000 €
Preferred heating technology: Gas condensing boiler + solar thermal (hot water)

If you had to give up, which details/expansions
-can you do without: Unfortunately, we can’t think of anything else at the moment, as we have already cut a variety of original wishes/ideas in the planning phase for cost reasons

Why did the design turn out the way it is now?
The unusual architecture with offset cubes arose based on our space requirement planning and at the same time fits our preferred style for residential buildings (inspired by Bauhaus style). Numerous adjustments and changes within the last 6 weeks with consultations with friends, builders, parents etc.

Additional questions:
1. We would like to preliminarily carry out the soil survey, clearing work and surveying at our own expense in order to submit these documents together with our design + a rough design construction description to various general contractors/general planners for the request for proposals. Does that make sense? What would be the best approach?
2. The property cannot currently be (sensibly) notarially transferred (from my parents to me), as the tax exemption limit has already been used up within the last 10 years. Could this lead to difficulties during construction or possibly restrict us regarding coordination appointments, land charge registration, etc.?
3. Where is there still potential for optimization in certain rooms/areas, also to possibly save some space?
4. We are aware that the cubic offset form leads to larger exterior surfaces = higher heating costs + more insulation material. Does this form lead to additional costs beyond that?

Just briefly on point 2: If the land does not belong to you, the house on it will not belong to you either. Who owns the land now? With the house on it, it is then worth more, so maybe the exemption won't apply after all?

Now to the floor plan, just unsorted things that catch my eye at first glance:
- The pantry is too narrow.
- To get to the kitchen or dining table, you always have to pass the living room. This looks too cramped on the floor plan with the drawn-in furniture, and on the other hand, you have no peace on the sofa.
- 50cm next to the bed is too little.
- You have planned storage space in the garage, but because of the climate, it is not suitable for all items.
- The entrance area is very/too spacious.
- The kitchen planning can still be optimized, e.g., there is currently no work surface between the sink and the stove. Seating at the stove is also rather suboptimal because of splashes.

I am aware of the issue. The property currently belongs to my father. We will only have the opportunity to apply the full €400,000 exemption for a gift again in 2029. The current plan is to register a kind of usufruct with the mortgage entry for the bank. (That means as long as I or my partner are alive, we may live on the property and use it according to our wishes).

But the house already costs more than 400k and the land is also worth something. How is it supposed to be transferred in 2029? I’m not familiar with [Nießbrauch], how it can be registered. Maybe it can be used to reduce the house value?

Now to the floor plan, just unsorted what catches my eye at first glance: - The pantry is too narrow. - To get to the kitchen or dining table, you always have to pass by the living room. On the floor plan with the drawn-in furniture, this looks too tight on the one hand, and on the other hand, you don’t have peace on the sofa. - 50cm next to the bed is too little. - You have planned storage space in the garage, but due to the climate, it is not suitable for all items. - The entrance area is very/too generous. - The kitchen layout can still be optimized, e.g. there is currently no workspace between the sink and the hob. Seats at the hob are also rather suboptimal because of splashing.

Thank you for the evaluation! - We moved a lot between pantry, stairs and utility room. Unfortunately, we cannot create more space without expanding the external dimensions and thus the floor areas again (= cost). The goal is to still use the space under the stairs sensibly. - The bed will be moved again to 80 cm passage width. - The floor area is already "too big" now, so additional storage areas will be difficult. - We will redesign sink and hob.