ᐅ Single-Family House on a Slope – Living Area on the Upper Floor, Open-Plan First Floor
Created on: 1 Apr 2026 13:34
B
Barnaby
Hello everyone,
we are planning a single-family house on a relatively steep slope (Northern Bavaria). An extension is mandatory, and the house shape is determined by the neighboring house.
The special feature is that we plan to live on the upper floor to have direct access to the terrace. Additionally, we want the upper floor to be open to the roof ridge—meaning no intermediate ceiling or attic space (no mezzanine, attic, etc.).
We really like the design. We are aware of the stairs (e.g., carrying groceries, etc.; water will come from a Quooker 😉...) but we still like the option of an upper-level terrace.
We have already received a turnkey offer from the general contractor, including our requests (parquet flooring, 4 m (13 ft) lift-and-slide door, 3 bathrooms) and exterior work, and we could start now. We are curious to hear what the professionals think, if there are any critical points we might have missed—we would build it like this!
Development plan/Restrictions
Plot size: 600 m2 (already owned)
Slope: yes, steep
Floor area ratio: 0.4 – 0.7
Floor space index: 0.47
Building window, building line, and boundary: determined by neighbor
Edge development: yes
Number of parking spaces: 2
Number of stories: 2 main floors + basement
Roof type: gable roof
Style: modern
Orientation:
Maximum height/limitations: none
Other requirements:
Homeowners’ requirements
Style, roof type, building type: single-family house with gable roof
Basement: yes
Number of floors: 2
Number of people: 2 adults (mid-30s) + 2 small children
Space requirements on ground and upper floors
Office: 4 days home office
Overnight guests per year: few
Open or closed layout: open
Conservative or modern construction: modern
Open kitchen, kitchen island: open kitchen with kitchen block
Number of dining seats: 8–10
Fireplace: no
Music/stereo wall: no
Balcony, roof terrace: no
Garage, carport: garage in basement
Utility garden, greenhouse: not currently, possibly later
House design
Origin of the design: based on existing floor plans from the internet + personal adjustments + adaptations with the general contractor’s planner
What do you particularly like? Why?
+ Open upper floor with high ceilings
+ Separate master suite
+ Separate children’s bathroom
What do you not like? ...mostly compromises we accept
- Rather tight space between the top of the stairs and entry on the ground floor
- Children’s bathroom without daylight
Price estimate according to architect/planner: offer from general contractor 750,000 including basement, incidental costs, fixtures, 100,000 for landscaping + groundworks
Personal price limit for the house, including features: 750,000
Preferred heating technology: heat pump
If you had to give up something, which details/extensions
- could you give up:
- could you not give up:
Why is the design the way it is?
The starting point was a found prefabricated house plan from the internet; we then swapped the ground and upper floors.
Other:
We will have a shaft prepared for an elevator (without the elevator). This will be left open in the floor slabs and will run from the garage → children’s bathroom → pantry upwards.
Thank you for your feedback
we are planning a single-family house on a relatively steep slope (Northern Bavaria). An extension is mandatory, and the house shape is determined by the neighboring house.
The special feature is that we plan to live on the upper floor to have direct access to the terrace. Additionally, we want the upper floor to be open to the roof ridge—meaning no intermediate ceiling or attic space (no mezzanine, attic, etc.).
We really like the design. We are aware of the stairs (e.g., carrying groceries, etc.; water will come from a Quooker 😉...) but we still like the option of an upper-level terrace.
We have already received a turnkey offer from the general contractor, including our requests (parquet flooring, 4 m (13 ft) lift-and-slide door, 3 bathrooms) and exterior work, and we could start now. We are curious to hear what the professionals think, if there are any critical points we might have missed—we would build it like this!
Development plan/Restrictions
Plot size: 600 m2 (already owned)
Slope: yes, steep
Floor area ratio: 0.4 – 0.7
Floor space index: 0.47
Building window, building line, and boundary: determined by neighbor
Edge development: yes
Number of parking spaces: 2
Number of stories: 2 main floors + basement
Roof type: gable roof
Style: modern
Orientation:
Maximum height/limitations: none
Other requirements:
Homeowners’ requirements
Style, roof type, building type: single-family house with gable roof
Basement: yes
Number of floors: 2
Number of people: 2 adults (mid-30s) + 2 small children
Space requirements on ground and upper floors
Office: 4 days home office
Overnight guests per year: few
Open or closed layout: open
Conservative or modern construction: modern
Open kitchen, kitchen island: open kitchen with kitchen block
Number of dining seats: 8–10
Fireplace: no
Music/stereo wall: no
Balcony, roof terrace: no
Garage, carport: garage in basement
Utility garden, greenhouse: not currently, possibly later
House design
Origin of the design: based on existing floor plans from the internet + personal adjustments + adaptations with the general contractor’s planner
What do you particularly like? Why?
+ Open upper floor with high ceilings
+ Separate master suite
+ Separate children’s bathroom
What do you not like? ...mostly compromises we accept
- Rather tight space between the top of the stairs and entry on the ground floor
- Children’s bathroom without daylight
Price estimate according to architect/planner: offer from general contractor 750,000 including basement, incidental costs, fixtures, 100,000 for landscaping + groundworks
Personal price limit for the house, including features: 750,000
Preferred heating technology: heat pump
If you had to give up something, which details/extensions
- could you give up:
- could you not give up:
Why is the design the way it is?
The starting point was a found prefabricated house plan from the internet; we then swapped the ground and upper floors.
Other:
We will have a shaft prepared for an elevator (without the elevator). This will be left open in the floor slabs and will run from the garage → children’s bathroom → pantry upwards.
Thank you for your feedback
Barnaby schrieb:
The offer for the exterior landscaping (€115,000, I mistakenly mentioned only €100,000 at the beginning) includes the retaining walls along the neighbor’s property and our house, underpinning of the neighbor’s retaining wall, L-shaped concrete blocks / support for our terrace after 10m (33 feet) uphill towards the slope, terracing of the southern outdoor areas, and groundworks.
Am I correct in understanding that you consider this completely unrealistic? Yes, I don’t think the groundworks are included.
Are you saying that it currently looks like this at the neighbor’s place (or similar)?
Glad we didn’t scare you off and that you’re still giving feedback.
ypg schrieb:
You mean that it is now like that with the neighbor (similar)? Yes, and he also has a canopy.
ypg schrieb:
Yes, I don’t think the groundwork is excluded. Basic excavation work is included according to the general contractor, provided the excavation material can be temporarily stored. However, we have also budgeted 36,000 for landfill disposal costs for uncontaminated soil, as included in the offer. Both the general contractor and we believe a significant amount can be reused for backfilling.
ypg schrieb:
Glad that we didn’t scare you off and that you’re still giving feedback. It’s a lively and interesting discussion; we appreciate constructive feedback of any kind (especially regarding the floor plan).
H
hanghaus20232 Apr 2026 16:55Here is my basement layout compared to your upper floor. This way, you only need two levels. This should help you stay within your budget. The house would then be set 1 meter (3 feet) higher. The ridge height would be 1 meter (3 feet) lower, just like the neighbor’s.
Between the carport and the entrance, a glass roof.
I didn’t quite understand the neighbor’s current situation. Are there no photos of the property with the neighbor’s house?
Between the carport and the entrance, a glass roof.
I didn’t quite understand the neighbor’s current situation. Are there no photos of the property with the neighbor’s house?
H
hanghaus20232 Apr 2026 17:04Barnaby schrieb:
Could you briefly explain what exactly you mean by excavation support for the basement foundation pit? Barnaby schrieb:
Underpinning of the neighboring retaining wall, If there is already a retaining wall on the boundary and it is being underpinned, you do not need additional excavation support. Proper underpinning is very expensive.
With my suggestion, you also need to underpin 1 m (3.3 ft) less.
D
derdietmar2 Apr 2026 19:10Hello,
The BayBO (Building Code) permits retaining walls up to 2 meters (6.5 feet) high at the property boundary. The natural ground level is always the relevant reference.
Assuming your plan is correct, the cross-section shows that the natural ground level on the west side, at the house wall, aligns exactly with the middle floor level. Therefore, you would need to raise an entire floor height with a retaining wall there. It now depends on the applicable building regulations. Obviously, there is a development plan, since boundary development is mandatory. Additionally, the exact construction of the neighbor’s wall is relevant.
If the existing structure is old enough, the building authority may protect it, even if the neighbor has excavated themselves. Therefore, I view the likelihood of approval somewhat critically. The neighbor’s approval is irrelevant; the specifications of the BayBO apply.
Some cost-related points have already been mentioned. The offer of 750,000 euros presumably applies to constructing the building itself (all red and green walls, turnkey). There is an offer for this, and the amount seems realistic for a simple contractor-built house with standard fittings.
However, earthworks and landscaping are not included; you probably will not get a fixed price for those. Due to the boundary construction, special stabilization measures and underpinning are necessary; you cannot simply excavate underneath your neighbor’s terrace.
Storing the excavated material temporarily will be a challenge, as only the west side of the property remains available for this. Because of the southern retaining walls outside the actual building and the required excavation slopes everywhere, an excavator cannot access the rear part of the site. Access would only be possible via another free plot located further south. The volume of excavated material is often severely underestimated, and it is questionable whether the available space, including the excavation slopes, will suffice.
The 100,000 euros will probably only cover the earthworks; if you need to store material off-site, costs will skyrocket. The landscaping itself, considering the many stairs and railings, will cost at least 50,000 euros if you contribute a lot of your own labor. Otherwise, it will likely be a six-figure sum.
Best regards
The BayBO (Building Code) permits retaining walls up to 2 meters (6.5 feet) high at the property boundary. The natural ground level is always the relevant reference.
Assuming your plan is correct, the cross-section shows that the natural ground level on the west side, at the house wall, aligns exactly with the middle floor level. Therefore, you would need to raise an entire floor height with a retaining wall there. It now depends on the applicable building regulations. Obviously, there is a development plan, since boundary development is mandatory. Additionally, the exact construction of the neighbor’s wall is relevant.
- Is the building depth limited, and has the neighbor fully utilized it?
- Is the wall on the neighbor’s side of your property a side wall of the lower terrace, on which the upper terrace rests (thus, from your perspective, acting as an exterior wall)?
If the existing structure is old enough, the building authority may protect it, even if the neighbor has excavated themselves. Therefore, I view the likelihood of approval somewhat critically. The neighbor’s approval is irrelevant; the specifications of the BayBO apply.
Some cost-related points have already been mentioned. The offer of 750,000 euros presumably applies to constructing the building itself (all red and green walls, turnkey). There is an offer for this, and the amount seems realistic for a simple contractor-built house with standard fittings.
However, earthworks and landscaping are not included; you probably will not get a fixed price for those. Due to the boundary construction, special stabilization measures and underpinning are necessary; you cannot simply excavate underneath your neighbor’s terrace.
Storing the excavated material temporarily will be a challenge, as only the west side of the property remains available for this. Because of the southern retaining walls outside the actual building and the required excavation slopes everywhere, an excavator cannot access the rear part of the site. Access would only be possible via another free plot located further south. The volume of excavated material is often severely underestimated, and it is questionable whether the available space, including the excavation slopes, will suffice.
The 100,000 euros will probably only cover the earthworks; if you need to store material off-site, costs will skyrocket. The landscaping itself, considering the many stairs and railings, will cost at least 50,000 euros if you contribute a lot of your own labor. Otherwise, it will likely be a six-figure sum.
Best regards
hanghaus2023 schrieb:
I didn’t understand the neighbor’s current situation. Why not? The original poster (OP) confirmed it as I described. Only that he also has a roof over his balcony. Exactly where Barnaby wants to have his terrace roof. Basically, Barnaby is adapting with his semi-detached house. It was just poorly communicated at the beginning.
hanghaus2023 schrieb:
Here’s my basement plan compared to your upper floor. Then you only need two floors. This way you’ll likely stay within budget. The house could be set 1 m (3 feet) higher. The ridge height, like the neighbor’s, would then be 1 m (3 feet) lower.
A glass roof between the carport and entrance. I don’t think anyone agrees to mashed potatoes when risotto was promised.
derdietmar schrieb:
The offer of 750,000 euros is probably for the construction of the building (all red and green walls, turnkey). There is an offer for this, and the amount seems realistic for a simple general contractor house with standard finishes. Yes, I think so too.
derdietmar schrieb:
The earthworks and landscaping are not included; you probably won’t get a fixed price for those. According to the scope of work, that includes 20 cm (8 inches) below the floor slab/basement. The rest will likely be extra.
derdietmar schrieb:
The temporary storage of excavation material will be problematic, That’s why there is also a detailed breakdown/extension of locations with disposal costs.
@Barnby, do you already have a detailed offer or scope of work where you can check what is only mentioned as a lump sum?
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