Plot selection - south slope with access from the north

Good evening everyone,
I am considering building a house on a meadow. The plot (family-owned) is located in the village (east of it a development area from the 90s – attached with Bebauungsplan_neu and marked in orange in the image – south of it a development area from the 80s – attached with Bebauungsplan_alt and marked in blue in the image), but it is not yet developed. Furthermore, another area will probably be developed in the future – marked in green in the attached image. In the attached image, you can see the plots, of which the larger meadow is owned by my parents – for example, I could choose '2' – while plot '1' is owned by my aunt.
The plot has a slope, descending to the south, and could be accessed from the north. The attached elevation profile from BayernAtlas does not correspond to reality. The slope falls off ‘significantly’ steeper (it’s all a question of relation). I do not have exact data on this but have tentatively measured at the western boundary of plot 1 with a cross-line laser from street level to the estimated front edge of the building (roughly at the height of the outbuilding) about 2m of height difference, as well as about 10m further back (estimated rear edge of the building) about 3.2m height difference. However, these measured points are where the steepest slope of the plot is; the eastern plot boundary is practically flat by comparison.
In both mentioned development areas, there are already renovated or rebuilt buildings or new constructions that no longer correspond to the original development plans. Nevertheless, I have filled out the requirements from both areas below as well as possible. The meadow, as mentioned, is not a development area and therefore officially has no development plan.
The basic desired property is a typical single-family house (2 children's rooms, 1 office). Since I currently want to build alone and am skilled in craftsmanship (I have already completely gutted two apartments of the 3-generation house of my parents with my father and grandfather – including electrical, heating, water, concrete, screed, doors, floors, etc.) I would initially want to build a shell and only finish the ground floor to save money. However, I do NOT want to discuss financing or question the feasibility based on my situation (yet). The financing will be clarified once a positive decision on the building inquiry and initial offers are available.

Now the question arises (assuming that the municipality supports development):
- Plot 1 (approx. 750 sqm) would be easier to develop and has less slope, but the purchase of the plot is not yet clarified (my aunt would basically like to swap – but then a survey as well as a swap including double notary, land registry fees, and property tax would have to be paid, and the plot would serve as her ‘retirement provision’ – to be sold if needed)
- Plot 2 has the disadvantage of a steeper slope and higher development costs. But the plot size is basically freely selectable, a sale of southwestern plot parts is less likely, and the plot would be basically free of charge.

Now the questions:
- Can one estimate how much one running meter of road costs (in Bavaria) in a municipality? The road above the plot is an asphalted but unusable land consolidation road and would definitely have to be replaced. The ‘new’ development plan shows a 4.5m wide road without sidewalk, which is also present in reality -> so I could find out at which point my aunt’s plot no longer makes sense or maybe someone can immediately give me a decisive argument for plot 1 or 2.

Development plan/restrictions
Plot size: approx. 750 sqm
Slope: yes, south slope (approx. 25° to the east) with access from the north
Floor area ratio: 0.4
Floor space index: 0.8
Building window, building line and boundary: currently none, as agricultural meadow, typical 3m
Edge development: only for outbuildings
Number of parking spaces: at least 2
Number of stories: ground floor + attic or ground floor + basement + attic (older development plan)
: gable roof with roof pitch of 38° … 48° in rafter or collar beam design
Style: open construction method
Orientation: unknown
Maximum heights/limits: unknown
Further requirements:
- Eaves height at top of slope min. 2.0m … max. 3.35m
- Eaves height at bottom of slope max. 6.3m
- Knee wall max. 0.5m
- Roof covering in beaver tails or tiles in natural red
- Roof overhang max. 0.3m or 0.5m (older development plan)
- Ground floor floor level must be above, but max. 0.3m or 0.5m (older development plan) above ground surface
- Exterior plaster as smooth or rough plaster

Requirements of the builders
Style, roof type, building type: gable roof
, stories: ground floor + basement (+ unused attic as storage)
Number of persons, age: 1 (30)
Space requirements on ground floor and upper floor: see floor plan idea
Office: home office
Occasional guests per year: unknown (sofa bed usually sufficient)
Open architecture
Conservative or modern style: mix
Open , freestanding kitchen island
Number of dining seats: min. 6
Fireplace: not necessary
Music/stereo wall: no
Balcony, roof terrace: balcony and terrace, easy access to the garden is important
Garage, carport: garage planned later, nothing at first

House design
Whose planning: do-it-yourself
What do you particularly like? Why?
- barrier-free conversion of the ground floor possible (study becomes bedroom, walls between bathroom, study, and storage room modified so that the bedroom has storage space for a wardrobe and the bathroom can be expanded)
- access from kitchen and dining area to large terrace/balcony
What do you not like? Why?
- natural light in (both) bathrooms questionable
- perhaps little space for a wardrobe?
- less space would be sufficient in the basement as well, therefore no bay window (questionable from a structural point of view – with/without supports)
- much wasted corridor space in the basement
Price estimate according to architect/planner: unknown
Personal price limit for the house, including equipment: unknown
Preferred heating technology: air-to-water heat pump

here are some ideas for the floor plan and a possible view of the house -> but first I want to clarify the property situation whether it could then be implemented that way - or how - would be discussed afterwards

The Bayernatlas does not lie. #2 has a 15% slope and #1 has a 10% slope. Provided the line corresponds to the direction of the slope.

"Slope: yes, south slope (approx. 25° to the east)" Then why are you measuring southeast in the Bayernatlas? Are the 25° really correct?

Tell me where you want to build. Then I can draw contour lines.

Is the meadow already building land?

okay, here is the railing relief. The property is not building land. A possible development was requested from the municipality a few years ago, and at least at that time the feedback was positive (yes, that doesn't have to mean anything today). The position of the house would basically be freely selectable within the plots. In plot 1 I would want to build as far west as possible, in the open meadow I would generally be open to suggestions

And unfortunately the Bayernatlas is already lying ...
in the terrain relief there is a steep slope in the middle (around the property boundary) which is not visible at all in the elevation profile. But exactly that is present.

I tried to take the measurement at about 90° to the street, as I assume that the ridge direction runs parallel to it.

The plot is not a building site. A possible development was inquired about with the municipality a few years ago, and at least back then the feedback was positive (yes, that doesn't mean anything today).

Then I would urgently start looking into the current status here. Are the plots even within the inner area? If not, then good luck for the next few years if anything can be done at all.